99 lines
2.5 KiB
C++
99 lines
2.5 KiB
C++
// Source : https://oj.leetcode.com/problems/combination-sum/
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// Author : Hao Chen
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// Date : 2014-07-19
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/**********************************************************************************
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*
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* Given a set of candidate numbers (C) and a target number (T), find all unique combinations
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* in C where the candidate numbers sums to T.
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*
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* The same repeated number may be chosen from C unlimited number of times.
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*
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* Note:
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*
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* All numbers (including target) will be positive integers.
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* Elements in a combination (a1, a2, … , ak) must be in non-descending order. (ie, a1 ≤ a2 ≤ … ≤ ak).
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* The solution set must not contain duplicate combinations.
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*
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* For example, given candidate set 2,3,6,7 and target 7,
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* A solution set is:
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* [7]
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* [2, 2, 3]
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*
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*
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**********************************************************************************/
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#include <iostream>
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#include <vector>
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#include <algorithm>
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using namespace std;
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void combinationSumHelper(vector<int> &candidates, int start, int target, vector<int> &solution, vector< vector<int> > &result) {
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if (target<0){
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return;
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}
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if (target==0){
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result.push_back(solution);
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return;
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}
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for(int i=start; i<candidates.size(); i++){
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//skip duplicates
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if (i>start && candidates[i] == candidates[i-1]) {
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continue;
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}
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solution.push_back(candidates[i]);
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combinationSumHelper(candidates, i, target - candidates[i], solution, result);
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solution.pop_back();
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}
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}
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vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
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vector< vector<int> > result;
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if (candidates.size()<=0){
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return result;
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}
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sort(candidates.begin(), candidates.end());
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vector<int> solution;
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combinationSumHelper(candidates, 0, target, solution, result);
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return result;
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}
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void printMatrix(vector< vector<int> > &vv)
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{
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for(int i=0; i<vv.size(); i++) {
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cout << "[";
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for(int j=0; j<vv[i].size(); j++) {
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cout << " " << vv[i][j];
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}
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cout << "]" << endl;;
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}
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}
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void printArray(vector<int> &v)
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{
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cout << "{";
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for(int i=0; i<v.size(); i++) {
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cout << " " << v[i];
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}
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cout << "}" << endl;
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}
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int main(int argc, char** argv)
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{
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int a[] = {4,2,3,3,5,7};
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vector<int> v(a, a+sizeof(a)/sizeof(int));
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int target = 7;
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cout << "array = ";
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printArray(v);
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cout << "target = " << target << endl;
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vector< vector<int> > vv = combinationSum(v, target);
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printMatrix(vv);
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return 0;
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}
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