最小路径覆盖模板题

#include
    
     #include
     
      #include
      
       #include
       
        #define maxn 155#define maxm 6005using namespace std;int n,m;struct edge{    int from;    int to;    int next;}E[maxm];int sz=0;int head[maxn];void add_edge(int u,int v){    sz++;    E[sz].from=u;    E[sz].to=v;    E[sz].next=head[u];    head[u]=sz;}int vis[maxn*2];int match[maxn*2];int dfs(int x){    for(int i=head[x];i;i=E[i].next){        int y=E[i].to;        if(!vis[y]){            vis[y]=1;            if(!match[y]||dfs(match[y])){                match[y]=x;                match[x]=y;                return 1;            }        }    }    return 0;}void print(int x){    x+=n;    do{        x-=n;        printf("%d ",x);        vis[x]=1;        x=match[x];    }while(x!=0);    printf("\n"); }int main(){    int x,y;    scanf("%d %d",&n,&m);    for(int i=1;i<=m;i++){        scanf("%d %d",&x,&y);        add_edge(x,y+n);     }    int ans=0;    for(int i=1;i<=n;i++){        memset(vis,0,sizeof(vis));        if(dfs(i)) ans++;    }    memset(vis,0,sizeof(vis));     for(int i=1;i<=n;i++){        if(!vis[i]){            print(i);        }    }    printf("%d\n",n-ans);}