[LeetCode] 118. Pascal's Triangle

思路:
简单模拟. 每一行除了头和尾是1, 剩下的是上一行第j - 1和第j两个元素的和.

vector<vector<int>> generate(int numRows) {    vector<vector<int>> res(numRows);    for (int i = 0; i < numRows; i++) {        res[i].resize(i + 1);        res[i][0] = res[i][i] = 1;        for (int j = 1; j < i; j++)            res[i][j] = res[i - 1][j - 1] + res[i - 1][j];    }    return res;}