#include using namespace std; int findLand(); void bfs(); void melt(); bool isVisit[301][301]; int ocean[301][301]; int N, M; queue> bfsQ; int main(){ cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(false); cin >> N >> M; for(int i = 0; i < N; i++){ for(int j = 0; j < M; j++){ cin >> ocean[i][j]; } } int ans = 0; int cnt = findLand(); while(cnt == 1){ melt(); cnt = findLand(); ans++; } if(!cnt){ ans = 0; } cout << ans << "\n"; return 0; } int findLand(){ memset(isVisit, false, sizeof(isVisit)); int cnt = 0; for(int i = 0; i < N; i++){ for(int j = 0; j < M; j++){ if(ocean[i][j] && !isVisit[i][j]){ bfsQ.push(make_pair(i, j)); isVisit[i][j] = true; bfs(); cnt++; } } } return cnt; } void bfs(){ while(!bfsQ.empty()){ int curX = bfsQ.front().first; int curY = bfsQ.front().second; bfsQ.pop(); int dx[4] = {0, 1, 0, -1}; int dy[4] = {1, 0, -1, 0}; for(int i = 0; i < 4; i++){ int newX = curX + dx[i]; int newY = curY + dy[i]; if(newX < 0 || newX >= N || newY < 0 || newY >= M){ continue; } if(ocean[newX][newY] && !isVisit[newX][newY]){ bfsQ.push(make_pair(newX, newY)); isVisit[newX][newY] = true; } } } } void melt(){ int tmp[301][301]; for(int i = 0; i < N; i++){ for(int j = 0; j < M; j++){ tmp[i][j] = 0; if(ocean[i][j]){ int dx[4] = {0, 1, 0, -1}; int dy[4] = {1, 0, -1, 0}; for(int p = 0; p < 4; p++){ int newX = i + dx[p]; int newY = j + dy[p]; if(newX < 0 || newX >= N || newY < 0 || newY >= M){ continue; } if(!ocean[newX][newY]){ tmp[i][j]++; } } } } } for(int i = 0; i < N; i++){ for(int j = 0; j < M; j++){ ocean[i][j] = max(ocean[i][j] - tmp[i][j], 0); } } }

2573. 빙산

2573. 빙산