delete pics to save space

history_source/挑战程序设计竞赛/2.6.4.1.cpp

@@ -0,0 +1,33 @@
+#include<cstdio>
+#define ll long long
+ll n;
+bool isp(ll n)
+{
+	static ll i;
+	for(i=2;i*i<=n;i++) if(n%i==0) return 0;
+	return n>1;
+}
+ll mod_pow(ll x,ll n,ll mod)
+{
+	static ll res;
+	res=1;
+	while(n>0)
+	{
+		if(n&1) res=res*x%mod;
+		x=x*x%mod;
+		n>>=1;
+	}
+	return res;
+}
+int solve()
+{
+	if(isp(n)) return printf("No\n");
+	for(ll i=2;i<n;i++) if(mod_pow(i,n,n)!=i) return printf("No\n");
+	printf("Yes\n");
+}
+int main()
+{
+	scanf("%lld",&n);
+	solve();
+	return 0;
+}