拓扑排序模板

【代码】

拓扑排序模板

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#include<set>
using namespace std;
#define f(i,n) for(int i=1;i<=(n);i++)
#define ll long long
#define INF 1<<30
#define N 100010
#define M 200010
int n,m;
int read()
{
 	int x=0,f=1;char c=getchar();
 	while(!isdigit(c)){if(c=='-')f=-1;c=getchar();}
 	while( isdigit(c)){x=x*10+c-'0';c=getchar();}
 	return x*f;
}
struct xj
{
	int y;
	int next;
}map[2*M];
int cnt;
int head[N];
void add_edge(int u,int v)
{
	map[++cnt].y=v;
	map[cnt].next=head[u];
	head[u]=cnt;
}
queue<int> q;
int rd[N],ans[N],vis[N];
void tp()
{
	f(i,n)if(!rd[i])q.push(i); 
	while(!q.empty())
	{
		int f=q.front();
		printf("%d ",f);
		q.pop();
		vis[f]=1;
		for(int i=head[f];i;i=map[i].next)
		{
			if(vis[map[i].y])continue;
			rd[map[i].y]--;
			if(!rd[map[i].y])q.push(map[i].y);
	    }
    }
}
int main()
{
	n=read();
	m=read();
	int u,v;
	f(i,m)
	{
		u=read();
		v=read();
		rd[v]++;
	    add_edge(u,v);
	} 
	tp();
}