编程之美—— Combination Sum

递归思想：

#include<iostream>#include<vector>#include<map>#include<algorithm>using namespace std;vector<vector<int> >  m_vecRet;void combination(const vector<int> &num, size_t idx, vector<int> &curr, int target){if (target == 0){m_vecRet.push_back(curr);}else{for (size_t i = idx; i < num.size(); ++i){if (i != idx && num[i] == num[i - 1]){continue;}if (target >= num[i]){   curr.push_back(num[i]);combination(num, i , curr, target - num[i]);curr.pop_back();}}}}vector<vector<int> > Combination_Sum(vector<int> &num, int target) {vector<int> vecTmp; m_vecRet.clear();sort(num.begin(), num.end());combination(num, 0, vecTmp, target);return m_vecRet;}int main(){int sum = 18;int data[3] = {7,2,3};vector<int> res(data, data + sizeof(data)/sizeof(int));vector<vector<int>> des;des = Combination_Sum(res,sum);for(int i = 0; i < des.size(); i++){for(vector<int>::iterator it = des[i].begin(); it != des[i].end();it++){cout<<*it<<" ";}cout<<endl;}cin.get();return 0;}