118. Pascal's Triangle Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 输出Pascal三角形的前n行:每次利用前面已经生成的行来生成下一行. 代码如下: class Solution { public: vector<vec…