uva4262

//传入图的大小n和邻接阵mat,不相邻点边权0
//需要调用强连通分支
#define MAXN 1002
#include<iostream>
#include<string.h>
using namespace std;
int mat[MAXN][MAXN];
int id[MAXN];
//传入图的大小n和邻接阵mat,不相邻点边权0
int find_components(int n,int mat[][MAXN],int* id){
int ret=0,a[MAXN],b[MAXN],c[MAXN],d[MAXN],i,j,k,t;
for (k=0;k<n;id[k++]=0);
for (k=0;k<n;k++)
if (!id[k]){
for (i=0;i<n;i++)
a[i]=b[i]=c[i]=d[i]=0;
a[k]=b[k]=1;
for (t=1;t;)
for (t=i=0;i<n;i++){
if (a[i]&&!c[i])
for (c[i]=t=1,j=0;j<n;j++)
if (mat[i][j]&&!a[j])
a[j]=1;
if (b[i]&&!d[i])
for (d[i]=t=1,j=0;j<n;j++)
if (mat[j][i]&&!b[j])
b[j]=1;
}
for (ret++,i=0;i<n;i++)
if (a[i]&b[i])
id[i]=ret;
}
return ret;
}

int main(){
    int t;
   cin>>t;
   while(t--){
       int n,m;
       memset(mat,0,sizeof(mat));
       cin>>n>>m;
       int x,y;
       for(int i=0;i<m;i++){
         cin>>x>>y;
          mat[x-1][y-1]=1;}
         
         cin>>x;
        
         int max=find_components(n,mat,id);
         cout<<max<<endl;
         }
    //system("pause");
    return 0;}

 

 

/*==================================================*/
| 无向图连通分支(dfs/bfs邻接阵)
| DFS / BFS / 并查集
/*==================================================*/
/*==================================================*/
| 有向图强连通分支(dfs/bfs邻接阵)O(n^2)
/*==================================================*/
//返回分支数,id返回1..分支数的值
//传入图的大小n和邻接阵mat,不相邻点边权0
#define MAXN 100
void search(int n,int mat[][MAXN],int* dfn,int* low,int now,int& cnt,int& tag,int* id,int* st,int& sp){
int i,j;
dfn[st[sp++]=now]=low[now]=++cnt;
for (i=0;i<n;i++)
if (mat[now][i]){
if (!dfn[i]){
search(n,mat,dfn,low,i,cnt,tag,id,st,sp);
if (low[i]<low[now])
low[now]=low[i];
}
else if (dfn[i]<dfn[now]){
for (j=0;j<sp&&st[j]!=i;j++);
if (j<cnt&&dfn[i]<low[now])
low[now]=dfn[i];
}
}
if (low[now]==dfn[now])
for (tag++;st[sp]!=now;id[st[--sp]]=tag);
}
int find_components(int n,int mat[][MAXN],int* id){
int ret=0,i,cnt,sp,st[MAXN],dfn[MAXN],low[MAXN];
for (i=0;i<n;dfn[i++]=0);
for (sp=cnt=i=0;i<n;i++)
if (!dfn[i])
search(n,mat,dfn,low,i,cnt,ret,id,st,sp);
return ret;
}
//有向图强连通分支,bfs邻接阵形式,O(n^2)
//返回分支数,id返回1..分支数的值
//传入图的大小n和邻接阵mat,不相邻点边权0
#define MAXN 100
int find_components(int n,int mat[][MAXN],int* id){
int ret=0,a[MAXN],b[MAXN],c[MAXN],d[MAXN],i,j,k,t;
for (k=0;k<n;id[k++]=0);
for (k=0;k<n;k++)
if (!id[k]){
for (i=0;i<n;i++)
a[i]=b[i]=c[i]=d[i]=0;
a[k]=b[k]=1;
for (t=1;t;)
for (t=i=0;i<n;i++){
if (a[i]&&!c[i])
for (c[i]=t=1,j=0;j<n;j++)
if (mat[i][j]&&!a[j])
a[j]=1;
if (b[i]&&!d[i])
for (d[i]=t=1,j=0;j<n;j++)
if (mat[j][i]&&!b[j])
b[j]=1;
}
for (ret++,i=0;i<n;i++)
if (a[i]&b[i])
id[i]=ret;
}
return ret;
}
/*==================================================*/