题目链接：https://pintia.cn/problem-sets/994805046380707840/problems/994805063963230208
基本上是裸的，直接看代码吧
1 #include<bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 const int inf=1<<30; 5 const double pi=acos(-1); 6 const int mod=998244353; 7 const int maxn=510; 8 const int maxm=6300; 9 int e[maxn][maxn];int n,m,cnt; 10 int vis[maxn]; 11 void dfs(int x){ 12 vis[x]=1; 13 for(int i=0;i<n;i++){ 14 if(!vis[i]&&e[x][i]){ 15 dfs(i); 16 } 17 } 18 } 19 int count(){ 20 int cnt=0; 21 memset(vis,0,sizeof(vis)); 22 for(int i=0;i<n;i++){ 23 if(!vis[i]){ 24 cnt++; 25 dfs(i); 26 } 27 } 28 return cnt; 29 } 30 int main(){ 31 scanf("%d%d",&n,&m); 32 int x,y; 33 for(int i=0;i<m;i++){ 34 scanf("%d%d",&x,&y); 35 e[x][y]=e[y][x]=1; 36 } 37 cnt=count(); 38 int k;scanf("%d",&k); 39 for(int i=0;i<k;i++){ 40 scanf("%d",&x); 41 for(int i=0;i<n;i++){ 42 if(e[x][i]){ 43 e[x][i]=e[i][x]=0; 44 } 45 } 46 int now=count(); 47 if(now-cnt>1){ 48 printf("Red Alert: City %d is lost! ",x); 49 }else{ 50 printf("City %d is lost. ",x); 51 }cnt=now; 52 if(i==n-1) { 53 printf("Game Over. ");break; 54 } 55 } 56 return 0; 57 }