delete pics to save space

1.3243.cpp

@@ -0,0 +1,44 @@
+#include<cstdio>
+#include<algorithm>
+#include<cassert>
+#include<queue>
+#include<cstring>
+#include<vector>
+using namespace std;
+const int maxn=100005;
+int T,n,m;
+vector<int> G[maxn];
+int in[maxn],res[maxn],cnt;
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d",&T);
+	while(T-->0)
+	{
+		scanf("%d%d",&n,&m);
+		for(int i=1;i<=n;i++) G[i].clear();
+		memset(in,0,sizeof(in)); cnt=0;
+		for(int i=0;i<m;i++)
+		{
+			int x,y; scanf("%d%d",&x,&y);
+			G[y].push_back(x); in[x]++;
+		}
+		priority_queue<int> Q;
+		for(int i=1;i<=n;i++) if(in[i]==0) Q.push(i);
+		while(Q.size())
+		{
+			int u=Q.top(); Q.pop(); res[cnt++]=u;
+			for(int v:G[u])
+			{
+				in[v]--;
+				if(!in[v]) Q.push(v);
+			}
+		}
+		for(int i=1;i<=n;i++) if(in[i]) { puts("Impossible!"); goto nxt; }
+		while(cnt) printf("%d ",res[--cnt]); puts("");
+		nxt:continue;
+	}
+	return 0;
+}