3*3网格中的总路径

def grid_paths(n):
    # 初始化一个n*n的二维数组
    grid = [[0 for _ in range(n)] for _ in range(n)]
    # 设置左上角的值为1
    grid[0][0] = 1
    # 填充第一行和第一列的值
    for i in range(1, n):
        grid[i][0] = 1
        grid[0][i] = 1
    # 填充其余的值
    for i in range(1, n):
        for j in range(1, n):
            grid[i][j] = grid[i-1][j] + grid[i][j-1]
    # 返回右下角的值
    return grid[-1][-1]

# 计算3*3网格中的总路径数量
print(grid_paths(3))