Submission

Score: 100

User: patty

Problemset: ย่องเบาหลบกับระเบิด

Language: cpp

Time: 0.056 second

Submitted On: 2026-03-04 12:32:46

#include <bits/stdc++.h>
using namespace std;
int main() {
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	int n,m,mindis=INT_MAX;
	cin >> n >> m;
	vector<vector<int>> mp(n,vector<int>(m,0));
	vector<vector<bool>> visited(n,vector<bool> (m,false));
	vector<vector<int>> dis(n,vector<int> (m,-1));
	int minex[] = {-1,-1,0,1,1,1,0,-1};
	int miney[] = {0,1,1,1,0,-1,-1,-1};
//x-1,y-1 x-1,y x-1,y+1
//x,y-1   x,y     x,y+1
//x+1,y-1 x+1,y   x+1,y+1
	for(int i=0;i<n;i++) {
		for(int j=0;j<m;j++) {
			cin >> mp[i][j];
		}
	}
	for(int i=0;i<n;i++) {
		for(int j=0;j<m;j++) {
			if(mp[i][j]==0) {
				for(int k=0;k<8;k++) {
					int ii = i + minex[k];
					int jj = j + miney[k];
					if(ii<0||jj<0||ii>n-1||jj>m-1) continue;
					if(mp[ii][jj]==1 && visited[ii][jj]==false) {
						visited[ii][jj] = true;
					}
				}
			}
		}
	}
//	for(int i=0;i<n;i++) {
//		for(int j=0;j<m;j++) {
//			cout << visited[i][j] << " ";
//		}
//		cout << "\n";
//		
//	}
	
	int dx[] = {-1,0,1,0};
	int dy[] = {0,1,0,-1};
	queue<pair<int,int>> q;
	for(int i=0;i<n;i++) {
		if(mp[i][0]==1 && !visited[i][0]) {
			q.push({i,0});
			visited[i][0]=true;
			dis[i][0]=1;
			
		}
	}
	while(!q.empty()) {
				int a = q.front().first;
				int b = q.front().second;
				q.pop();
				for(int j=0;j<4;j++) {
					int aa = a + dx[j];
					int bb = b + dy[j];
					if(aa<0||bb<0||aa>n-1||bb>m-1) continue;
					if(mp[aa][bb]==1 && visited[aa][bb]==false) {
						q.push({aa,bb});
						visited[aa][bb] = true;
						dis[aa][bb] = dis[a][b] + 1;
					}
				}
			}
	for(int i=0;i<n;i++) {
		if(dis[i][m-1]!=-1 && visited[i][m-1]) {
			mindis = min(mindis,dis[i][m-1]);
		}
	}
	if(mindis<INT_MAX) cout << mindis;
	else cout << "-1";
//	for(int i=0;i<n;i++) {
//		for(int j=0;j<m;j++) {
//			cout << dis[i][j] << " ";
//		}
//		cout << "\n";
//	}
}