文章作者：Tyan
博客：noahsnail.com | CSDN | 简书
1. Description
Island Perimeter
2. Solution
class Solution {
public:
int islandPerimeter(vector<vector<int>>& grid) {
int perimeter = 0;
int rows = grid.size();
int columns = grid[0].size();
for(int i = 0; i < rows; i++) {
for(int j = 0; j < columns; j++) {
if(grid[i][j]) {
getPerimeter(grid, i, j, perimeter, rows, columns);
return perimeter;
}
}
}
}
private:
void getPerimeter(vector<vector<int>>& grid, int i, int j, int& perimeter, int& rows, int& columns) {
if(i < 0 || i == rows || j < 0 || j == columns || grid[i][j] == 0) {
perimeter++;
return;
}
if(grid[i][j] == -1) {
return;
}
grid[i][j] = -1;
getPerimeter(grid, i + 1, j, perimeter, rows, columns);
getPerimeter(grid, i - 1, j, perimeter, rows, columns);
getPerimeter(grid, i, j + 1, perimeter, rows, columns);
getPerimeter(grid, i, j - 1, perimeter, rows, columns);
}
};
