「luogu2764」最小路径覆盖问题

#include<bits/stdc++.h>
using namespace std;
const int N=160,M=6010;
int n,m,link[N<<1];
vector<int>point[N<<1];
bool used[N<<1],start[N];
bool find(int k){
    for(int i=0;i<point[k].size();i++)if(!used[point[k][i]]){
        used[point[k][i]]=1;
        if(!link[point[k][i]]||find(link[point[k][i]])){
            link[point[k][i]]=k;
            return 1;
        }
    }
    return 0;
}
bool vis[N];
int main(){
    int t1,t2,ans=0;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++){
        scanf("%d%d",&t1,&t2);
        point[t2].push_back(t1+n);
    }
    for(int i=1;i<=n;i++){
        memset(used,0,sizeof(used));
        if(find(i)) ans++;
    }
    ans=n-ans;
    for(int i=1;i<=n;i++){
        if(vis[i]) continue;
        vis[i]=1;
        t1=link[i+n];
        while(t1){
            vis[t1]=start[t1]=1;
            t1=link[t1+n];
        }
    }
    for(int i=1;i<=n;i++)if(!start[i]){
        t1=i;
        while(t1){
            printf("%d ",t1);
            t1=link[t1+n];
        }
        printf("
");
    }
    printf("%d",ans);
}