백준 2468번 C++ 풀이

#include <iostream>
#include <queue>
#include <vector>
using namespace std;
int delta[4][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};

bool isVisited[101][101];
int buffer[101][101];
int main() {
    cin.tie(NULL);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;
    for (auto i=0; i<n; i++){
        for (auto j=0; j<n; j++){
            cin >> buffer[i][j];
        }
    }
    int answer = 0;


    for (auto height = 0; height <= 100; height++ ){
        for (auto i=0; i<n; i++){
            for (auto j=0; j<n; j++){
                isVisited[i][j] = false;
            }
        }
        int safe_area = 0;
        for (auto i=0; i<n; i++){
            for (auto j=0; j<n; j++){
                if ( !isVisited[i][j] && (buffer[i][j] > height)){
                    safe_area++;

                    isVisited[i][j] = true;
                    queue<pair<int, int>> q;
                    q.push(make_pair(i,j));
                    while (!q.empty()){

                        auto top = q.front();
                        q.pop();
                        for (auto k=0; k<4; k++){
                            auto next_x = top.first + delta[k][0];
                            auto next_y = top.second + delta[k][1];

                            if (0 <= next_x && next_x < n && 0 <= next_y && next_y < n){
                                if (!isVisited[next_x][next_y] && (buffer[next_x][next_y] > height)){
                                    isVisited[next_x][next_y] = true;
                                    q.push(make_pair(next_x,next_y));
                                }

                            }
                        }
                    }

                }
            }
        }
        answer = max(answer,safe_area);

    }
    cout << answer;
    return 0;

}