Leetcode_38combinationsum [combination sum]

#pragma warning(disable:4996)#include <cstdio>#include <tchar.h>#include <Windows.h>#include <vector>using namespace std;/*submit time : 41.Runtime ErrorLast executed input:[1], 2// Find it2. Wrong AnswerInput:[2,3,5], 7Output:[[2,2,3]]Expected:[[2,2,3],[2,5]]3. Wrong AnswerInput:[1,2], 2Output:[[1,1],[2],[2]]Expected:[[1,1],[2]]request :Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.The same repeated number may be chosen from C unlimited number of times.Note:All numbers (including target) will be positive integers.Elements in a combination (a1, a2, … , ak) must be in non-descending order. (ie, a1 ≤ a2 ≤ … ≤ ak).The solution set must not contain duplicate combinations.For example, given candidate set 2,3,6,7 and target 7,A solution set is:[7][2, 2, 3]*///=================QuickSort===================void Swap(int* data, int i, int j) {int temp = data[i];data[i] = data[j];data[j] = temp;}int findpivot(int* data, int i, int j) {return (i + j) >> 1;}int partition(int* data, int l, int r, int pivot) {while (l < r) {while (data[++l] < pivot);while (l<r && data[--r] > pivot);Swap(data, l, r);}return l;}void qsort(int* data, int i, int j) {if (j <= i) return;int pivotIndex = findpivot(data, i, j);Swap(data, pivotIndex, j);int k = partition(data, i - 1, j, data[j]);Swap(data, k, j);qsort(data, i, k - 1);qsort(data, k + 1, j);}//===================END=======================void helpCombinationSum(vector<vector<int> >& result, vector<int>& solution, int* pStart, int* pLast, int* vernier, int target) {if (target == 0) {result.push_back(solution);return;}if ((vernier <= pLast && target < *vernier) || (vernier > pLast))return;int currValue = *vernier;int maxCount = target / currValue;int rem = target % currValue;int i = maxCount;while (i) {solution.push_back(currValue);--i;}while (maxCount >= 0) {helpCombinationSum(result, solution, pStart, pLast, vernier + 1, target - currValue*maxCount);if (maxCount)solution.pop_back();--maxCount;}}vector<vector<int> > combinationSum(vector<int> &candidates, int target) {vector<vector<int> > result;if (candidates.size() == 0) return result;vector<int> solution;int* vernier = &candidates[0];int length = candidates.size();int* firstCandidate = vernier;int* lastCandidate = vernier + length - 1;// sort candidatesqsort(vernier, 0, length - 1);// submit failed here/*while (vernier <= lastCandidate) {helpCombinationSum(result, solution, firstCandidate, lastCandidate, vernier, target);++vernier;}*/helpCombinationSum(result, solution, firstCandidate, lastCandidate, vernier, target);return result;}//======================Test========================void printVector(vector<int>& num) {vector<int>::iterator iter = num.begin();for (; iter != num.end(); ++iter)printf("%d ", *iter);printf("\n");}void Test() {//int data[] = { 9, 31, 25, 5, 8, 6, 16 };int data[] = { 2,3,5 };int target = 7;vector<int> candidates(data, data + sizeof(data) / sizeof(int));vector<vector<int> > result = combinationSum(candidates, target);vector<vector<int> >::iterator iter = result.begin();for (; iter != result.end(); ++iter)printVector(*iter);}int _tmain(int argc, _TCHAR* argv[]) {Test();system("pause");return 0; }