119. Pascal's Triangle II

119. Pascal's Triangle II

Given an index (k), return the (k^{th}) row of the Pascal's triangle.

For example, given (k = 3),
Return [1,3,3,1].

直接生成由0组成的数组,设定a[0] = 1,迭代生成最后结果.
纯人家代码,不易理解:

vector<int> getRow(int rowIndex) {
    vector<int> A(rowIndex + 1, 0);
    A[0] = 1;
    for (int i = 1; i < rowIndex + 1; i++)
        for (int j = i; j >= 1; j--)
            A[j] += A[j - 1];
    return A;
}