delete pics to save space

8.2242.cpp

@@ -0,0 +1,79 @@
+#include<cstdio>
+#include<cmath>
+#include<algorithm>
+#include<map>
+using namespace std;
+typedef long long LL;
+LL ksm(LL a,LL b,LL p)
+{
+	LL res=1;
+	for(;b;b>>=1,a=a*a%p) b&1?res=res*a%p:0;
+	return res;
+}
+LL exgcd(LL a,LL b,LL &x,LL &y)
+{
+	if(b==0) { x=1; y=0; return a; }
+	LL d=exgcd(b,a%b,y,x);
+	y-=x*(a/b);
+	return d;
+}
+int T,K;
+void a()
+{
+	while(T-->0)
+	{
+		LL y,z,p; scanf("%lld%lld%lld",&y,&z,&p);
+		printf("%lld\n",ksm(y,z,p));
+	}
+}
+void b()
+{
+	while(T-->0)
+	{
+		LL y,z,p,x,r; scanf("%lld%lld%lld",&y,&z,&p);
+		LL d=exgcd(y,p,x,r);
+		if(z%d) puts("Orz, I cannot find x!");
+		else printf("%lld\n",(z/d*x%p+p)%p);
+	}
+}
+LL BSGS(LL a,LL b,LL p)
+{
+	b%=p;
+	map<LL,int> mp;
+	int t=(int)sqrt(p)+1;
+	LL x=b,y=ksm(a,t,p);
+	if(y==0) return b==0?1:-1;
+	for(int j=0;j<=t-1;j++)
+	{
+		mp[x]=j;
+		x=x*a%p;
+	}
+	x=1;
+	for(int i=0,j;i<=t;i++)
+	{
+		if(mp.find(x)!=mp.end()&&i*t-(j=mp[x])>=0) return i*t-j;
+		x=x*y%p;
+	}
+	return -1;
+}
+void c()
+{
+	while(T-->0)
+	{
+		LL y,z,p; scanf("%lld%lld%lld",&y,&z,&p);
+		LL d=BSGS(y,z,p);
+		if(d==-1) puts("Orz, I cannot find x!");
+		else printf("%lld\n",d);
+	}
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d%d",&T,&K);
+	if(K==1) a();
+	else if(K==2) b();
+	else c();
+	return 0;
+}