1 //SPOJ - UOFTCG 树的最小路径覆盖 2 3 #include <bits/stdc++.h> 4 #include <vector> 5 using namespace std; 6 #define ll long long 7 const int mod = 1e9+7; 8 const int maxn=510; 9 const int N = 1e5+10; 10 int cnt; 11 int head[N]; 12 struct edge{ 13 int to,next; 14 }e[N<<2]; 15 void addedge(int u,int v){ 16 e[cnt].to=v,e[cnt].next=head[u],head[u]=cnt++; 17 e[cnt].to=u,e[cnt].next=head[v],head[v]=cnt++; 18 } 19 20 int cov[N]; 21 bool vis[N],used[N]; 22 void dfs(int u,int f){ 23 used[u]=1; 24 cov[u]=1; 25 int tot=0; 26 for(int i=head[u];~i;i=e[i].next){ 27 int v=e[i].to; 28 if(v==f) continue; 29 dfs(v,u); 30 cov[u]+=cov[v]; 31 if(!vis[v]) tot++; 32 } 33 if(tot>=2) cov[u]-=2,vis[u]=1; 34 else if(tot==1) cov[u]-=1; 35 } 36 int main(){ 37 // freopen("in.txt","r",stdin); 38 int T; 39 scanf("%d",&T); 40 while(T--){ 41 cnt=0; 42 memset(used,false,sizeof(used)); 43 memset(head,-1,sizeof(head)); 44 memset(cov,0,sizeof(cov)); 45 memset(vis,false,sizeof(vis)); 46 int n,m; 47 scanf("%d%d",&n,&m); 48 for(int i=1;i<=m;i++){ 49 int u,v; 50 scanf("%d%d",&u,&v); 51 addedge(u,v); 52 } 53 int ans=0; 54 for(int i=1;i<=n;i++){ 55 if(!used[i]) dfs(i,0),ans+=cov[i]; 56 } 57 // cout<<cov[1]<<endl; 58 printf("%d ",ans+n-1); 59 } 60 }