delete pics to save space

1.2661.cpp

@@ -0,0 +1,28 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=200005;
+int n,res=1e9+7,T[maxn],dfn[maxn],vis[maxn],cnt;
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d",&n);
+	for(int i=1;i<=n;i++) scanf("%d",&T[i]);
+	for(int i=1;i<=n;i++)
+		if(!dfn[i])
+		{
+			memset(vis,0,sizeof(vis));
+			int x=i;
+			while(!dfn[x])
+			{
+				dfn[x]=++cnt; vis[x]=true;
+				x=T[x];
+			}
+			if(vis[x]) res=min(res,cnt+1-dfn[x]);
+		}
+	printf("%d\n",res);
+	return 0;
+}