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;
    }