New Problem Solution -"Number of Different Integers in a String"

README.md

@@ -9,6 +9,7 @@ LeetCode
 
 | # | Title | Solution | Difficulty |
 |---| ----- | -------- | ---------- |
+|1805|[Number of Different Integers in a String](https://leetcode.com/problems/number-of-different-integers-in-a-string/) | [C++](./algorithms/cpp/numberOfDifferentIntegersInAString/NumberOfDifferentIntegersInAString.cpp)|Easy|
 |1803|[Count Pairs With XOR in a Range](https://leetcode.com/problems/count-pairs-with-xor-in-a-range/) | [C++](./algorithms/cpp/countPairsWithXorInARange/CountPairsWithXorInARange.cpp)|Hard|
 |1802|[Maximum Value at a Given Index in a Bounded Array](https://leetcode.com/problems/maximum-value-at-a-given-index-in-a-bounded-array/) | [C++](./algorithms/cpp/maximumValueAtAGivenIndexInABoundedArray/MaximumValueAtAGivenIndexInABoundedArray.cpp)|Medium|
 |1801|[Number of Orders in the Backlog](https://leetcode.com/problems/number-of-orders-in-the-backlog/) | [C++](./algorithms/cpp/numberOfOrdersInTheBacklog/NumberOfOrdersInTheBacklog.cpp)|Medium|

algorithms/cpp/numberOfDifferentIntegersInAString/NumberOfDifferentIntegersInAString.cpp

@@ -0,0 +1,77 @@
+// Source : https://leetcode.com/problems/number-of-different-integers-in-a-string/
+// Author : Hao Chen
+// Date   : 2021-03-28
+
+/***************************************************************************************************** 
+ *
+ * You are given a string word that consists of digits and lowercase English letters.
+ * 
+ * You will replace every non-digit character with a space. For example, "a123bc34d8ef34" will become 
+ * " 123  34 8  34". Notice that you are left with some integers that are separated by at least one 
+ * space: "123", "34", "8", and "34".
+ * 
+ * Return the number of different integers after performing the replacement operations on word.
+ * 
+ * Two integers are considered different if their decimal representations without any leading zeros 
+ * are different.
+ * 
+ * Example 1:
+ * 
+ * Input: word = "a123bc34d8ef34"
+ * Output: 3
+ * Explanation: The three different integers are "123", "34", and "8". Notice that "34" is only 
+ * counted once.
+ * 
+ * Example 2:
+ * 
+ * Input: word = "leet1234code234"
+ * Output: 2
+ * 
+ * Example 3:
+ * 
+ * Input: word = "a1b01c001"
+ * Output: 1
+ * Explanation: The three integers "1", "01", and "001" all represent the same integer because
+ * the leading zeros are ignored when comparing their decimal values.
+ * 
+ * Constraints:
+ * 
+ * 	1 <= word.length <= 1000
+ * 	word consists of digits and lowercase English letters.
+ ******************************************************************************************************/
+
+class Solution {
+private:
+    bool isNumber(char ch) {
+        return (ch >='0' && ch <='9');
+    }
+    
+public:
+    int numDifferentIntegers(string word) {
+        word.push_back('z'); // add a char for edge case.
+        bool intStart = false; // a stat for control 
+        int start = 0, len = 0;
+        unordered_map<string, bool> stat;
+        for(int i=0; i<word.size(); i++) {
+            if (!isNumber(word[i]) ) {
+                if (intStart) {
+                    while(word[start]=='0') {
+                        start++, len--;
+                    }
+                    stat[word.substr(start, len)] = true;
+                    intStart=false; 
+                }
+                continue;
+            }
+            
+            if (intStart == false) {
+                intStart = true;
+                start = i;
+                len = 1;
+            }else {
+                len++;
+            }
+        }
+        return stat.size();           
+    }
+};