Leetcode#118 Pascal's Triangle

原题地址

基本模拟题

代码：

vector<vector<int> > generate(int numRows) {
        vector<vector<int> > res;
        
        if (numRows <= 0)
            return res;
            
        res.push_back(vector<int>(1, 1));
        while (--numRows) {
            vector<int> layer;
            layer.push_back(1);
            for (int i = 0; i + 1 < res.back().size(); i++)
                layer.push_back(res.back()[i] + res.back()[i + 1]);
            layer.push_back(1);
            res.push_back(layer);
        }
        
        return res;
}