剑指offer python版 二维数组的查找

def find_integer(matrix, num):
    """
    :param matrix: [[]]
    :param num: int
    :return: bool
    """
    if not matrix:
        return False
    rows, cols = len(matrix), len(matrix[0])
    row, col = rows - 1, 0
    while row >= 0 and col <= cols - 1:
        if matrix[row][col] == num:
            return True
        elif matrix[row][col] > num:
            row -= 1
        else:
            col += 1
    return False