//运用了数学知识
int* getRow(int rowIndex, int* returnSize) {
    *returnSize = rowIndex + 1;
    int* row = malloc(sizeof(int) * (*returnSize));
    row[0] = 1;
    for (int i = 1; i <= rowIndex; ++i) {
        row[i] = 1LL * row[i - 1] * (rowIndex - i + 1) / i;
    }
    return row;
}