added some python solutions
This commit is contained in:
Kurt-Yu
Hao Chen
parent
555706f880
commit
afd100954f
19
README.md
19
README.md
@ -8,6 +8,7 @@ LeetCode
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| # | Title | Solution | Difficulty |
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|---| ----- | -------- | ---------- |
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|971|[Flip Binary Tree To Match Preorder Traversal](https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal/) | [Python](./algorithms/python/FlipBinaryTreeToMatchPreorderTraversal/flipMatchVoyage.py)|Medium|
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|958|[Check Completeness of a Binary Tree](https://leetcode.com/problems/check-completeness-of-a-binary-tree/) | [Python](./algorithms/python/CheckCompletenessOfABinaryTree/isCompleteTree.py)|Medium|
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|951|[Flip Equivalent Binary Trees](https://leetcode.com/problems/flip-equivalent-binary-trees/) | [Python](./algorithms/python/FlipEquivalentBinaryTrees/flipEquiv.py)|Medium|
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|859|[Buddy Strings](https://leetcode.com/problems/buddy-strings/description/) | [C++](./algorithms/cpp/buddyStrings/BuddyStrings.cpp)|Easy|
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@ -17,6 +18,7 @@ LeetCode
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|837|[Most Common Word](https://leetcode.com/problems/most-common-word/) | [C++](./algorithms/cpp/mostCommonWord/MostCommonWord.cpp)|Easy|
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|804|[Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words/description/) | [C++](./algorithms/cpp/uniqueMorseCodeWords/UniqueMorseCodeWords.cpp)|Easy|
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|771|[Jewels and Stones](https://leetcode.com/problems/jewels-and-stones/description) | [C++](./algorithms/cpp/jewelsAndStones/JewelsAndStones.cpp)|Easy|
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|687|[Longest Univalue Path](https://leetcode.com/problems/longest-univalue-path/) | [Python](./algorithms/python/LongestUnivaluePath/longestUnivaluePath.py)|Easy|
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|684|[Redundant Connection](https://leetcode.com/problems/redundant-connection/) | [Python](./algorithms/python/RedundantConnection/findRedundantConnection.py)|Medium|
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|671|[Second Minimum Node In a Binary Tree](https://leetcode.com/problems/second-minimum-node-in-a-binary-tree/) | [Python](./algorithms/python/SecondMinimumNodeInABinaryTree/findSecondMinimumValue.py)|Easy|
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|662|[Maximum Width of Binary Tree](https://leetcode.com/problems/maximum-width-of-binary-tree/) | [Python](./algorithms/python/MaximumWidthOfBinaryTree/widthOfBinaryTree.py)|Medium|
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@ -31,6 +33,7 @@ LeetCode
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|477|[Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/) | [C++](./algorithms/cpp/totalHammingDistance/totalHammingDistance.cpp)|Medium|
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|450|[DeleteNodeInABST](https://leetcode.com/problems/delete-node-in-a-bst/) | [Python](./algorithms/python/DeleteNodeInABST/deleteNode.py)|Medium|
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|449|[Serialize and Deserialize BST](https://leetcode.com/problems/serialize-and-deserialize-bst/) | [Python](./algorithms/python/SerializeAndDeserializeBST/serialize.py)|Medium|
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|437|[Path Sum III](https://leetcode.com/problems/path-sum-iii/) | [Python](./algorithms/python/PathSumIII/pathSum.py)|Medium|
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|418|[SentenceScreenFitting](https://leetcode.com/problems/sentence-screen-fitting/) ♥ | [C++](./algorithms/cpp/sentenceScreenFitting/sentenceScreenFitting.cpp)|Easy|
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|416|[Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/description/) | [C++](./algorithms/cpp/partitionEqualSubsetSum/PartitionEqualSubsetSum.cpp)|Medium|
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|415|[Add Strings](https://leetcode.com/problems/add-strings/) | [C++](./algorithms/cpp/addStrings/AddStrings.cpp)|Easy|
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@ -204,8 +207,8 @@ LeetCode
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|151|[Reverse Words in a String](https://oj.leetcode.com/problems/reverse-words-in-a-string/)| [C++](./algorithms/cpp/reverseWordsInAString/reverseWordsInAString.cpp), [Java](./algorithms/java/src/reverseWordsInAString/ReverseWordsInAString.java)|Medium|
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|150|[Evaluate Reverse Polish Notation](https://oj.leetcode.com/problems/evaluate-reverse-polish-notation/)| [C++](./algorithms/cpp/evaluateReversePolishNotation/evaluateReversePolishNotation.cpp)|Medium|
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|149|[Max Points on a Line](https://oj.leetcode.com/problems/max-points-on-a-line/)| [C++](./algorithms/cpp/maxPointsOnALine/maxPointsOnALine.cpp)|Hard|
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|148|[Sort List](https://oj.leetcode.com/problems/sort-list/)| [C++](./algorithms/cpp/sortList/sortList.cpp)|Medium|
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|147|[Insertion Sort List](https://oj.leetcode.com/problems/insertion-sort-list/)| [C++](./algorithms/cpp/insertionSortList/insertionSortList.cpp)|Medium|
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|148|[Sort List](https://oj.leetcode.com/problems/sort-list/)| [C++](./algorithms/cpp/sortList/sortList.cpp), [Python](./algorithms/python/SortList/sortList.py)|Medium|
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|147|[Insertion Sort List](https://oj.leetcode.com/problems/insertion-sort-list/)| [C++](./algorithms/cpp/insertionSortList/insertionSortList.cpp), [Python](./algorithms/python/InsertionSortList/insertionSortList.py)|Medium|
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|146|[LRU Cache](https://oj.leetcode.com/problems/lru-cache/)| [C++](./algorithms/cpp/LRUCache/LRUCache.cpp), [Java](./algorithms/java/src/lruCache/LRUCache.java)|Hard|
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|145|[Binary Tree Postorder Traversal](https://oj.leetcode.com/problems/binary-tree-postorder-traversal/)| [C++](./algorithms/cpp/binaryTreePostorderTraversal/binaryTreePostorderTraversal.cpp), [Python](./algorithms/python/BinaryTreePostorderTraversal/postorderTraversal.py)|Hard|
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|144|[Binary Tree Preorder Traversal](https://oj.leetcode.com/problems/binary-tree-preorder-traversal/)| [C++](./algorithms/cpp/binaryTreePreorderTraversal/binaryTreePreorderTraversal.cpp), [Java](./algorithms/java/src/binaryTreePreorderTraversal/binaryTreePreorderTraversal.java)|Medium|
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@ -254,23 +257,23 @@ LeetCode
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|101|[Symmetric Tree](https://oj.leetcode.com/problems/symmetric-tree/)| [C++](./algorithms/cpp/symmetricTree/symmetricTree.cpp)|Easy|
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|100|[Same Tree](https://oj.leetcode.com/problems/same-tree/)| [C++](./algorithms/cpp/sameTree/sameTree.cpp)|Easy|
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|99|[Recover Binary Search Tree](https://oj.leetcode.com/problems/recover-binary-search-tree/)| [C++](./algorithms/cpp/recoverBinarySearchTree/recoverBinarySearchTree.cpp)|Hard|
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|98|[Validate Binary Search Tree](https://oj.leetcode.com/problems/validate-binary-search-tree/)| [C++](./algorithms/cpp/validateBinarySearchTree/validateBinarySearchTree.cpp), [Java](./algorithms/java/src/validateBinarySearchTree/validateBinarySearchTree.java)|Medium|
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|98|[Validate Binary Search Tree](https://oj.leetcode.com/problems/validate-binary-search-tree/)| [C++](./algorithms/cpp/validateBinarySearchTree/validateBinarySearchTree.cpp), [Java](./algorithms/java/src/validateBinarySearchTree/validateBinarySearchTree.java), [Python](./algorithms/python/ValidateBinarySearchTree/isValidBST.py)|Medium|
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|97|[Interleaving String](https://oj.leetcode.com/problems/interleaving-string/)| [C++](./algorithms/cpp/interleavingString/interleavingString.cpp)|Hard|
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|96|[Unique Binary Search Trees](https://oj.leetcode.com/problems/unique-binary-search-trees/)| [C++](./algorithms/cpp/uniqueBinarySearchTrees/uniqueBinarySearchTrees.cpp), [Python](./algorithms/python/UniqueBinarySearchTrees/numTrees.py)|Medium|
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|95|[Unique Binary Search Trees II](https://oj.leetcode.com/problems/unique-binary-search-trees-ii/)| [C++](./algorithms/cpp/uniqueBinarySearchTrees/uniqueBinarySearchTrees.II.cpp)|Medium|
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|95|[Unique Binary Search Trees II](https://oj.leetcode.com/problems/unique-binary-search-trees-ii/)| [C++](./algorithms/cpp/uniqueBinarySearchTrees/uniqueBinarySearchTrees.II.cpp), [Python](./algorithms/python/UniqueBinarySearchTreesII/generateTrees.py)|Medium|
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|94|[Binary Tree Inorder Traversal](https://oj.leetcode.com/problems/binary-tree-inorder-traversal/)| [C++](./algorithms/cpp/binaryTreeInorderTraversal/binaryTreeInorderTraversal.cpp)|Medium|
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|93|[Restore IP Addresses](https://oj.leetcode.com/problems/restore-ip-addresses/)| [C++](./algorithms/cpp/restoreIPAddresses/restoreIPAddresses.cpp)|Medium|
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|92|[Reverse Linked List II](https://oj.leetcode.com/problems/reverse-linked-list-ii/)| [C++](./algorithms/cpp/reverseLinkedList/reverseLinkedList.II.cpp), [Java](./algorithms/java/src/reverseLinkedListII/ReverseLinkedListII.java)|Medium|
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|92|[Reverse Linked List II](https://oj.leetcode.com/problems/reverse-linked-list-ii/)| [C++](./algorithms/cpp/reverseLinkedList/reverseLinkedList.II.cpp), [Java](./algorithms/java/src/reverseLinkedListII/ReverseLinkedListII.java), [Python](./algorithms/python/ReverseLinkedListII/reverseBetween.py)|Medium|
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|91|[Decode Ways](https://oj.leetcode.com/problems/decode-ways/)| [C++](./algorithms/cpp/decodeWays/decodeWays.cpp)|Medium|
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|90|[Subsets II](https://oj.leetcode.com/problems/subsets-ii/)| [C++](./algorithms/cpp/subsets/subsets.II.cpp), [Java](./algorithms/java/src/subsets/subsetsII.java)|Medium|
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|89|[Gray Code](https://oj.leetcode.com/problems/gray-code/)| [C++](./algorithms/cpp/grayCode/grayCode.cpp)|Medium|
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|88|[Merge Sorted Array](https://oj.leetcode.com/problems/merge-sorted-array/)| [C++](./algorithms/cpp/mergeTwoSortedArray/mergeTwoSortedArray.cpp)|Easy|
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|87|[Scramble String](https://oj.leetcode.com/problems/scramble-string/)| [C++](./algorithms/cpp/scrambleString/scrambleString.cpp)|Hard|
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|86|[Partition List](https://oj.leetcode.com/problems/partition-list/)| [C++](./algorithms/cpp/partitionList/partitionList.cpp)|Medium|
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|86|[Partition List](https://oj.leetcode.com/problems/partition-list/)| [C++](./algorithms/cpp/partitionList/partitionList.cpp), [Python](./algorithms/python/PartitionList/partition.py)|Medium|
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|85|[Maximal Rectangle](https://oj.leetcode.com/problems/maximal-rectangle/)| [C++](./algorithms/cpp/maximalRectangle/maximalRectangle.cpp)|Hard|
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|84|[Largest Rectangle in Histogram](https://oj.leetcode.com/problems/largest-rectangle-in-histogram/)| [C++](./algorithms/cpp/largestRectangleInHistogram/largestRectangleInHistogram.cpp)|Hard|
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|83|[Remove Duplicates from Sorted List](https://oj.leetcode.com/problems/remove-duplicates-from-sorted-list/)| [C++](./algorithms/cpp/removeDuplicatesFromSortedList/removeDuplicatesFromSortedList.cpp)|Easy|
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|82|[Remove Duplicates from Sorted List II](https://oj.leetcode.com/problems/remove-duplicates-from-sorted-list-ii/)| [C++](./algorithms/cpp/removeDuplicatesFromSortedList/removeDuplicatesFromSortedList.II.cpp)|Medium|
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|82|[Remove Duplicates from Sorted List II](https://oj.leetcode.com/problems/remove-duplicates-from-sorted-list-ii/)| [C++](./algorithms/cpp/removeDuplicatesFromSortedList/removeDuplicatesFromSortedList.II.cpp), [Python](./algorithms/python/RemoveDuplicatesFromSortedListII/deleteDuplicates.py)|Medium|
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|81|[Search in Rotated Sorted Array II](https://oj.leetcode.com/problems/search-in-rotated-sorted-array-ii/)| [C++](./algorithms/cpp/searchInRotatedSortedArray/searchInRotatedSortedArray.II.cpp)|Medium|
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|80|[Remove Duplicates from Sorted Array II](https://oj.leetcode.com/problems/remove-duplicates-from-sorted-array-ii/)| [C++](./algorithms/cpp/removeDuplicatesFromSortedArray/removeDuplicatesFromSortedArray.II.cpp)|Medium|
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|79|[Word Search](https://oj.leetcode.com/problems/word-search/)| [C++](./algorithms/cpp/wordSearch/wordSearch.cpp)|Medium|
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@ -333,7 +336,7 @@ LeetCode
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|22|[Generate Parentheses](https://oj.leetcode.com/problems/generate-parentheses/)| [C++](./algorithms/cpp/generateParentheses/generateParentheses.cpp)|Medium|
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|21|[Merge Two Sorted Lists](https://oj.leetcode.com/problems/merge-two-sorted-lists/)| [C++](./algorithms/cpp/mergeTwoSortedList/mergeTwoSortedList.cpp)|Easy|
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|20|[Valid Parentheses](https://oj.leetcode.com/problems/valid-parentheses/)| [C++](./algorithms/cpp/validParentheses/validParentheses.cpp)|Easy|
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|19|[Remove Nth Node From End of List](https://oj.leetcode.com/problems/remove-nth-node-from-end-of-list/)| [C++](./algorithms/cpp/removeNthNodeFromEndOfList/removeNthNodeFromEndOfList.cpp)|Easy|
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|19|[Remove Nth Node From End of List](https://oj.leetcode.com/problems/remove-nth-node-from-end-of-list/)| [C++](./algorithms/cpp/removeNthNodeFromEndOfList/removeNthNodeFromEndOfList.cpp), [Python](./algorithms/python/RemoveNthNodeFromEndOfList/removeNthFromEnd.py)|Easy|
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|18|[4Sum](https://oj.leetcode.com/problems/4sum/)| [C++](./algorithms/cpp/4Sum/4Sum.cpp)|Medium|
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|17|[Letter Combinations of a Phone Number](https://oj.leetcode.com/problems/letter-combinations-of-a-phone-number/)| [C++](./algorithms/cpp/letterCombinationsOfAPhoneNumber/letterCombinationsOfAPhoneNumber.cpp)|Medium|
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|16|[3Sum Closest](https://oj.leetcode.com/problems/3sum-closest/)| [C++](./algorithms/cpp/3SumClosest/3SumClosest.cpp)|Medium|
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@ -0,0 +1,12 @@
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def flipMatchVoyage(self, root, voyage):
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res = []
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self.i = 0
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def dfs(root):
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if not root: return True
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if root.val != voyage[self.i]: return False
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self.i += 1
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if root.left and root.left.val != voyage[self.i]:
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res.append(root.val)
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root.left, root.right = root.right, root.left
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return dfs(root.left) and dfs(root.right)
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return res if dfs(root) else [-1]
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19
algorithms/python/InsertionSortList/insertionSortList.py
Normal file
19
algorithms/python/InsertionSortList/insertionSortList.py
Normal file
@ -0,0 +1,19 @@
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def insertionSortList(self, head):
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if not head: return head
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dummy = ListNode(0)
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curr = head
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prev = dummy
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while curr:
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next = curr.next
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while prev.next and prev.next.val < curr.val:
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prev = prev.next
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curr.next = prev.next
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prev.next = curr
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prev = dummy
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curr = next
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return dummy.next
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11
algorithms/python/LongestUnivaluePath/longestUnivaluePath.py
Normal file
11
algorithms/python/LongestUnivaluePath/longestUnivaluePath.py
Normal file
@ -0,0 +1,11 @@
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def longestUnivaluePath(self, root):
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self.longest = 0
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def helper(root):
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if not root: return 0
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l, r = helper(root.left), helper(root.right)
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left = (l + 1) if root.left and root.left.val == root.val else 0
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right = (r + 1) if root.right and root.right.val == root.val else 0
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self.longest = max(self.longest, left + right)
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return max(left, right)
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helper(root)
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return self.longest
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14
algorithms/python/PartitionList/partition.py
Normal file
14
algorithms/python/PartitionList/partition.py
Normal file
@ -0,0 +1,14 @@
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def partition(self, head, x):
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h1 = l1 = ListNode(0)
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h2 = l2 = ListNode(0)
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while head:
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if head.val < x:
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l1.next = head
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l1 = l1.next
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else:
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l2.next = head
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l2 = l2.next
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head = head.next
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l2.next = None
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l1.next = h2.next
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return h1.next
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21
algorithms/python/PathSumIII/pathSum.py
Normal file
21
algorithms/python/PathSumIII/pathSum.py
Normal file
@ -0,0 +1,21 @@
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def pathSum(self, root, target):
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self.result = 0
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cache = {0:1}
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def dfs(root, currPathSum):
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if not root: return
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currPathSum += root.val
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oldPathSum = currPathSum - target
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self.result += cache.get(oldPathSum, 0)
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cache[currPathSum] = cache.get(currPathSum, 0) + 1
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dfs(root.left, currPathSum)
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dfs(root.right, currPathSum)
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cache[currPathSum] -= 1
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dfs(root, 0)
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return self.result
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@ -0,0 +1,13 @@
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def deleteDuplicates(self, head):
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dummy = prev = ListNode(0)
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dummy.next = head
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while head and head.next:
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if head.val == head.next.val:
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while head and head.next and head.val == head.next.val:
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head = head.next
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head = head.next
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prev.next = head
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else:
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prev = prev.next
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head = head.next
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return dummy.next
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@ -0,0 +1,10 @@
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def removeNthFromEnd(self, head, n):
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slow = fast = head
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for i in range(n):
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fast = fast.next
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if not fast: return head.next
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while fast.next:
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fast = fast.next
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slow = slow.next
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slow.next = slow.next.next
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return head
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14
algorithms/python/ReverseLinkedListII/reverseBetween.py
Normal file
14
algorithms/python/ReverseLinkedListII/reverseBetween.py
Normal file
@ -0,0 +1,14 @@
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def reverseBetween(self, head, m, n):
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if not head or n == m: return head
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p = dummy = ListNode(0)
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dummy.next = head
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for _ in range(m - 1):
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p = p.next
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tail = p.next
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for _ in range(n - m):
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temp = p.next
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p.next = tail.next
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tail.next = tail.next.next
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p.next.next = temp
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return dummy.next
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37
algorithms/python/SortList/sortList.py
Normal file
37
algorithms/python/SortList/sortList.py
Normal file
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# merge sort:
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def sortList(self, head):
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if not head or not head.next: return head
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leftHalf, rightHalf = self.split(head)
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left = self.sortList(leftHalf)
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right = self.sortList(rightHalf)
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return self.mergeSorted(left, right)
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def mergeSorted(self, a, b):
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res = dummy = ListNode(0)
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while a and b:
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if a.val < b.val:
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dummy.next = a
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dummy = a
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a = a.next
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else:
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dummy.next = b
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dummy = b
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b = b.next
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if not a: dummy.next = b
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else: dummy.next = a
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return res.next
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def split(self, node):
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if not node or not node.next:
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return node, None
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slow, fast = node, node
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prev = None
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while fast.next:
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prev = slow
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slow = slow.next
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fast = fast.next.next
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if not fast: break
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prev.next = None
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return node, slow
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24
algorithms/python/UniqueBinarySearchTreesII/generateTrees.py
Normal file
24
algorithms/python/UniqueBinarySearchTreesII/generateTrees.py
Normal file
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def generateTrees(self, n):
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if n == 0: return []
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def helper(start, end):
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ls = []
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if start > end:
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ls.append(None)
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return ls
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if start == end:
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ls.append(TreeNode(start))
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return ls
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for i in range(start, end + 1):
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left = helper(start, i - 1)
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right = helper(i + 1, end)
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for lnode in left:
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for rnode in right:
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root = TreeNode(i)
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root.left = lnode
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root.right = rnode
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ls.append(root)
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return ls
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return helper(1, n)
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26
algorithms/python/ValidateBinarySearchTree/isValidBST.py
Normal file
26
algorithms/python/ValidateBinarySearchTree/isValidBST.py
Normal file
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# method 1: using recursion
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|
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def isValidBST1(self, root, lower = float('-inf'), upper = float('inf')):
|
||||
"""
|
||||
:type root: TreeNode
|
||||
:rtype: bool
|
||||
"""
|
||||
if not root: return True
|
||||
if root.val <= lower or root.val >= upper: return False
|
||||
return self.isValidBST(root.left, lower, min(upper, root.val)) \
|
||||
and self.isValidBST(root.right, max(lower, root.val), upper)
|
||||
|
||||
|
||||
# method 2: a proper BST should have this porperty: inorder traversal is increasing
|
||||
def isValidBST2(self, root):
|
||||
inorder = []
|
||||
def helper(root):
|
||||
if root:
|
||||
helper(root.left)
|
||||
inorder.append(root.val)
|
||||
helper(root.right)
|
||||
|
||||
helper(root)
|
||||
for i in range(len(inorder) - 1):
|
||||
if inorder[i + 1] <= inorder[i]: return False
|
||||
return True
|
||||
Loading…
x
Reference in New Issue
Block a user