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[LeetCode] 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] 

Solution:

int differentCandidatesNum;int* differentCandidates;int* differentCandidatesCount;vector<vector<int> > ans;int targ;void dfs(int k, int curSum, vector<int> curCount){    /*    cout << "k = " << k << " curSum = " << curSum << endl;    cout << "curCount: ";    for(int i = 0;i < curCount.size();i++)        cout << curCount[i] << " ";    cout << endl;    */    if(curSum > targ)         return;    if(curSum == targ)    {        vector<int> curCom;        for(int i = 0;i < curCount.size();i++)            for(int j = 0;j < curCount[i];j++)                curCom.push_back(differentCandidates[i]);        ans.push_back(curCom);        return;    }    if(k >= differentCandidatesNum)         return;    //try the k the no duplicate candidates    //choose 0 to differentCandidatesCount[k]‘s k to check if this is a good combination    for(int i = 0;i <= differentCandidatesCount[k];i++)    {        curCount.push_back(i);        dfs(k + 1, curSum + i * differentCandidates[k], curCount);        curCount.pop_back();    }}vector<vector<int> > combinationSum2(vector<int> &num, int target) {        if(num.size() == 0) return ans;        //sort the candidate num        for(int i = 0;i < num.size();i++)        {            bool continueBubble = false;            for(int j = 0;j < num.size() - i - 1;j++)            {                if(num[j] > num[j + 1])                {                    int tmp = num[j];                    num[j] = num[j + 1];                    num[j + 1] = tmp;                    continueBubble = true;                }            }            if(continueBubble == false)                break;        }        //get no duplicate candidates        int curNum = num[0], counter = 1;        differentCandidates = new int[num.size()];        differentCandidatesCount = new int[num.size()];        differentCandidatesNum = 0;                for(int i = 1;i < num.size();i++)        {            if(curNum == num[i])             {                counter++;            }            else            {                differentCandidates[differentCandidatesNum] = curNum;                differentCandidatesCount[differentCandidatesNum] = counter;                differentCandidatesNum++;                counter = 1;                curNum = num[i];            }        }        //add last no duplicate candidate        differentCandidates[differentCandidatesNum] = curNum;        differentCandidatesCount[differentCandidatesNum] = counter;        differentCandidatesNum++;    //    for(int i = 0;i < differentCandidatesNum;i++)    //        cout << differentCandidates[i] << " num = " << differentCandidatesCount[i] << endl;                //begin dfs to search combinations.        targ = target;        vector<int> cur;        dfs(0, 0, cur);        delete [] differentCandidates;        return ans;    }