[力扣题解] 695. 岛屿的最大面积

题目：695. 岛屿的最大面积

思路

代码

深度优先搜索

// 深度搜索
class Solution {
private:int area_max = 0;int dir[4][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};void dfs(vector<vector<int>>& grid, vector<vector<bool>>& visited, int x, int y, int& area){int m = grid.size(), n = grid[0].size();int i, j;int next_x, next_y;for(i = 0; i < 4; i++){next_x = x + dir[i][0];next_y = y + dir[i][1];if(next_x < 0 || next_x >= m || next_y < 0 || next_y >= n){continue;} if(!visited[next_x][next_y] && grid[next_x][next_y] == 1){visited[next_x][next_y] = true;area++;dfs(grid, visited, next_x, next_y, area);}}}public:int maxAreaOfIsland(vector<vector<int>>& grid) {int m = grid.size(), n = grid[0].size();int i, j;int area = 0, area_max = 0;vector<vector<bool>> visited(m, vector<bool>(n, 0));for(i = 0; i < m; i++){for(j = 0; j < n; j++){if(!visited[i][j] && grid[i][j] == 1){area = 1;visited[i][j] = true;dfs(grid, visited, i, j, area);if(area_max < area){area_max = area;}}}}return area_max;}
};