c_cpp 463.cpp

Posted 2021-05-14

class Solution {
public:
    int islandPerimeter(vector<vector<int>>& grid) {
        int count = 0, repeat = 0, n = grid.size(), m = grid[0].size();
        for(int i = 0; i < n; i++) {
            for(int j = 0; j < m; j++) {
                if (grid[i][j] == 1) {
                    count++;
                    if (i != 0 && grid[i-1][j] == 1) repeat++;
                    if (j != 0 && grid[i][j-1] == 1)  repeat++;
                }
            }
        }
        return 4*count - repeat*2;
    }
};