119. Pascal's Triangle II

    vector<int> getRow(int rowIndex) {                vector<int> res;        if(rowIndex<0) return res;        res.assign(rowIndex+1,0);        for(int i=0;i<=rowIndex;i++){            if(i==0)            {                 res[i]=1;                continue;            }            for(int j=rowIndex;j>0;j--){                res[j]+=res[j-1];            }        }          return res;    }