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前言

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一、``173. 矩阵距离（acwing）

import java.io.*;
import java.util.*;
public class Main {static int N=1010;static int n,m;static char[][] a=new char[N][N];static int[][] b=new int[N][N];static Queue<int[]> queue=new LinkedList<>();static boolean[][] st=new boolean[N][N];static int[] dx={1,-1,0,0};static int[] dy={0,0,1,-1};static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));static StreamTokenizer sth = new StreamTokenizer(br);static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));public static void main(String[] args) throws Exception {n=nextInt();m=nextInt();for (int i = 0; i <n; i++) {a[i]=br.readLine().toCharArray();for (int j = 0; j <m; j++) {if (a[i][j]=='1'){st[i][j]=true;queue.offer(new int[]{i,j});}}}int tmp=0;while (!queue.isEmpty()){int size=queue.size();while (size-->0){int[] curr=queue.poll();int x=curr[0];int y=curr[1];b[x][y]=tmp;for (int i = 0; i < 4; i++) {int newX=x+dx[i];int newY=y+dy[i];if (newX>=0&&newX<n&&newY>=0&&newY<m&&!st[newX][newY]){queue.offer(new int[]{newX,newY});st[newX][newY]=true;}}}tmp++;}for (int i = 0; i < n; i++) {for (int j = 0; j < m; j++) {out.print(b[i][j]+" ");}out.println();}out.flush();}// 读入整形（一个）public static int nextInt() throws Exception {sth.nextToken();return (int) sth.nval; // nval 读入的是 double 类型}
}

二、5475 聚会

#include <bits/stdc++.h>using namespace std;
const int N = 100010, M = 2 * N;
int n, m, k, s;
int dist[N][101];
int h[N], e[M], ne[M], idx;
int q[N];void add(int a, int b) {e[idx] = b, ne[idx] = h[a], h[a] = idx ++ ;
}void bfs(vector<int> &begin, int c) {int hh = 0, tt = -1;for(int i = 1;i <= n; ++ i) dist[i][c] = 1e9;for(auto it: begin) {q[ ++ tt] = it;dist[it][c] = 0;}while(hh <= tt) {auto u = q[hh ++ ];for(int i = h[u]; ~i; i = ne[i]) {int j = e[i];if(dist[j][c] > dist[u][c] + 1) {dist[j][c] = dist[u][c] + 1;q[ ++ tt] = j;}}}
}void work(int u) {static int tmp[101];int cnt = 0;for(int i = 1;i <= k; ++ i) tmp[i] = dist[u][i];sort(tmp + 1, tmp + k + 1);int res = 0;for(int i = 1;i <= s; ++ i) res += tmp[i];printf("%d ", res);
}int main() {cin >> n >> m >> k >> s;    memset(h, -1, sizeof h);vector<int> a(n + 1);vector<vector<int>> color(k + 1);for(int i = 1;i <= n; ++ i) {scanf("%d", &a[i]);color[a[i]].push_back(i);}while(m -- ) {int u, v;scanf("%d%d", &u, &v);add(u, v), add(v, u);}for(int i = 1;i <= k; ++ i) {bfs(color[i], i);}for(int i = 1;i <= n; ++ i) work(i);return 0;
}

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