problem
solution:
class Solution { public: int islandPerimeter(vector<vector<int>>& grid) { if(grid.empty()) return 0; int m=grid.size(), n=grid[0].size(); int ans = 0; for(int i=0; i<m; i++) { for(int j=0; j<n; j++) { if(grid[i][j]==0) continue; if(j==0 || grid[i][j-1]==0) ans++; if(j==n-1 || grid[i][j+1]==0) ans++; if(i==0 || grid[i-1][j]==0) ans++; if(i==m-1 || grid[i+1][j]==0) ans++; } } return ans; } };
参考
1. Leetcode_463. Island Perimeter;
完