int numIslands(char** grid, int gridSize, int* gridColSize){
    //找递归边界
    if(grid == NULL || gridSize == 0)
    {
        return 0;
    }
    int row = gridSize;//行数
    int col = *gridColSize;//列数
    int count = 0;//用于计数
    int i = 0;
    int j = 0;
    //遍历这个二维网格
    for(i = 0; i < row; i++)
    {
        for(j = 0; j < col; j++)
        {
            if(grid[i][j] == '1')
            {
                count++;
                //将‘1’周围的‘1’全部同化成0
                dfs(grid, i, j, row, col);
            }
        }
    }
    return count;
}
void dfs(char** grid, int x, int y, int row, int col)
{
    //判断特殊情况
    if(x < 0 || x >= row || y < 0 || y >= col || grid[x][y] == '0')//注意哦，下标等于行数列数时也是不可以的哟，还要加上grid[x][y]是否为0这个判断条件
    {
        return;
    }
    grid[x][y] = '0';
    dfs(grid, x - 1, y, row, col);
    dfs(grid, x + 1, y, row, col);
    dfs(grid, x, y - 1, row, col);
    dfs(grid, x, y + 1, row, col);
}