首页 > 代码库 > Combination Sum II

Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.

Each number in C may only be used once in the combination.

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 10,1,2,7,6,1,5 and target 8
A solution set is: 
[1, 7] 
[1, 2, 5] 
[2, 6] 
[1, 1, 6] 

C++实现代码:

#include<iostream>#include<vector>#include<algorithm>using namespace std;class Solution {public:    vector<vector<int> > combinationSum2(vector<int> &num, int target){        if(num.empty())            return vector<vector<int> >();        sort(num.begin(),num.end());        vector<vector<int> > ret;        vector<int> path;        combination(num,0,target,ret,path);        return ret;    }    void combination(vector<int> &candidates,int start,int target,vector<vector<int> > &ret,vector<int> &path)    {        if(target<0)            return;        if(target==0)        {            ret.push_back(path);            return;        }        int i;        for(i=start;i<(int)candidates.size();i++)        {            if(i>start&&candidates[i]==candidates[i-1])                continue;            path.push_back(candidates[i]);            combination(candidates,i+1,target-candidates[i],ret,path);            path.pop_back();        }    }};int main(){    Solution s;    vector<int> vec={0,0,10,1,2,7,6,1,5};    vector<vector<int> > result=s.combinationSum2(vec,8);    for(auto a:result)    {        for(auto v:a)            cout<<v<<" ";        cout<<endl;    }}

运行结果:

Combination Sum II