题目：

题解：

class Solution:
    def islandPerimeter(self, grid: List[List[int]]) -> int:
        row=len(grid)
        col=len(grid[0])
        nums=0
        c=0
        grid=grid+[[0]*col]
        for i in range(row):
            grid[i].append(0)
            for j in range(col):
                if grid[i][j]==1:
                    nums+=1
                if grid[i][j]==1 and grid[i+1][j]==1:
                    c-=2
                if grid[i][j]==1 and grid[i][j+1]==1:
                    c-=2
        c+=nums*4
        return c