463. Island Perimeter

Java

public class Solution {
    public int islandPerimeter(int[][] grid) {
        int count=0;
        for(int i=0;i<grid.length;i++)
        {
            for(int j=0;j<grid[i].length;j++)
            {
                if(grid[i][j]==1)
                {
                int tmp=4;
                if(i>=1&&grid[i-1][j]==1)
                tmp--;
                if(i<grid.length-1&&grid[i+1][j]==1)
                tmp--;
                if(j>=1&&grid[i][j-1]==1)
                tmp--;
                if(j<grid[i].length-1&&grid[i][j+1]==1)
                tmp--;
                count+=tmp;
                }
            }
        }
        return count;
    }
}

Javascript

/**
 * @param {number[][]} grid
 * @return {number}
 */
var islandPerimeter = function(grid) {
    var count=0;
        for(var i=0;i<grid.length;i++)
        {
            for(var j=0;j<grid[i].length;j++)
            {
                if(grid[i][j]==1)
                {
                var tmp=4;
                if(i>=1&&grid[i-1][j]==1)
                tmp--;
                if(i<grid.length-1&&grid[i+1][j]==1)
                tmp--;
                if(j>=1&&grid[i][j-1]==1)
                tmp--;
                if(j<grid[i].length-1&&grid[i][j+1]==1)
                tmp--;
                count+=tmp;
                }
            }
        }
        return count;
};

优解，思路差不多，想法要好一点