백준 16234 인구이동(bfs)

https://www.acmicpc.net/problem/16234

16234번: 인구 이동

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<queue>
#include<vector>
#include<algorithm>
#include<string>
#include<string.h>
#define ABS(a) ((a<0)?(a*-1):(a))
using namespace std;

int N, L, R;
int map[51][51];
int visited[51][51];
int sum[2503][2];
int groupNumber; 
int dy[] = { 1,0,-1,0 }; 
int dx[] = { 0,1,0,-1 };
queue <pair<int,int > > q;
void bfs(int x, int y,int gn) {
	q.push(make_pair(x, y));
	visited[x][y] = gn;

	while (!q.empty()) {
		int cx = q.front().first;
		int cy = q.front().second;
		sum[gn][0]++;
		sum[gn][1] += map[cx][cy];
		q.pop();
		for (int i = 0; i < 4; i++) {
			int nx = cx + dx[i];
			int ny = cy + dy[i];
			int diff = ABS((map[cx][cy] - map[nx][ny]));
			if (nx >= 0 && ny >= 0 && nx < N && ny < N && diff >= L && diff <= R && visited[nx][ny] == 0) {
				q.push(make_pair(nx, ny));
				visited[nx][ny] = gn;
			}
		}
	}
	
}
int main() {
	int t=0;
	scanf("%d%d%d", &N, &L, &R);
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			scanf("%d", &map[i][j]);
		}
	}

	while (1) {
		int groupNumber = 1;
		memset(sum, 0, sizeof(sum));
		memset(visited, 0, sizeof(visited));
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				if (visited[i][j] == 0) {
					bfs(i,j,groupNumber);
					groupNumber++;
				}
			}
		}

		if (groupNumber-1 >= N * N) {
			printf("%d", t);
			break;
		}

		t++;

		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				int chk = visited[i][j];
				map[i][j] = sum[chk][1] / sum[chk][0];
			}
		}

	}
		
}