AcWing 173. 矩阵距离
原题链接
简单
作者:
整天睡大觉
,
2024-04-19 09:29:01
,
所有人可见
,
阅读 2
#include <iostream>
#include <cstring>
#include <algorithm>
#define x first
#define y second
using namespace std;
typedef pair<int, int> PII;
const int N = 1010,M = N * N;
int n, m;
int g[N][N];
int dist[N][N];
bool st[N][N];
PII q[M];
void bfs(){
int hh = 0, tt = -1;
int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
for(int i = 0; i < n; i ++){
for(int j = 0; j < m; j ++){
if(g[i][j] == 1){
q[++ tt] = {i , j};
dist[i][j] = 0;
st[i][j] = true;
}
}
}
while(hh <= tt){
auto t = q[hh ++];
for(int i = 0; i < 4; i ++){
int a = t.x + dx[i], b = t.y + dy[i];
if(a < 0 || a >= n || b < 0 || b >= m) continue;
if(st[a][b]) continue;
dist[a][b] = dist[t.x][t.y] + 1;
st[a][b] = true;
q[++ tt] = {a, b};
}
}
}
int main()
{
cin >> n >> m;
for(int i = 0; i < n; i ++)
for(int j = 0; j < m; j ++)
scanf("%1d", &g[i][j]);
bfs();
for(int i = 0; i < n; i ++){
for (int j = 0; j < m; j ++ ){
cout << dist[i][j] << ' ';
}
puts("");
}
return 0;
}