BZOJ 4010: [HNOI2015]菜肴制作

<span style="font-size:18px;">#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
const int N=100000+5;
struct Edge{int to,next;}e
;
int head
,cnt;
void ins(int u,int v){
e[++cnt]=(Edge){v,head[u]};head[u]=cnt;
}
int deg
;
priority_queue<int>q;
int a
,tot;
void solve(int u){
q.pop();a[++tot]=u;
for(int i=head[u];i;i=e[i].next){
int v=e[i].to;
deg[v]--;
if(!deg[v])q.push(v);
}
}
int main(){
//freopen("a.in","r",stdin);
int T;scanf("%d",&T);
while(T--){
int n,m;scanf("%d%d",&n,&m);
memset(deg,0,sizeof(deg));
memset(head,0,sizeof(head));cnt=0;
while(m--){
int u,v;scanf("%d%d",&u,&v);ins(v,u);
deg[u]++;
}
while(!q.empty())q.pop();
for(int i=1;i<=n;i++)if(!deg[i])q.push(i);
tot=0;
while(!q.empty())solve(q.top());
if(tot!=n)puts("Impossible!");
else{
for(int i=n;i;i--)
printf("%d ",a[i]);
putchar('\n');
}
}
return 0;
}</span>