uva11549 Floyd判圈法

题意：

给两个数n, k,每次将k平方取k的前n位，问所有出现过的数的最大值

原来这就是floyd判圈法。。

 #include<cstdio>
 #include<cstdlib>
 #include<algorithm>
 #include<iostream>
 #include<cstring>
 #include<string>

 template<typename Q> Q read(Q& x) {
     static char c;
     static bool f;
     for(f = ; c = getchar(), !isdigit(c); ) if(c == '-') f = ;
     for(x = ; isdigit(c); c = getchar()) x = x *  + c - '';
     if(f) x = -x; return x;
 }
 template<typename Q> Q read() {
     static Q x; read(x); return x;
 }

 typedef long long LL;

 int next(int n, int x) {
     LL x2 = (LL) x * x;
     int len = ;
     for(LL t = x2; t; t /= ) len++;
     if(len > n) for(int t = len - n; t--; x2 /= );
     return x2;
 }

 int main() {
 #ifdef DEBUG
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w", stdout);
 #endif

     int T = read<int>();
     while(T--) {
         int n = read<int>(), k = read<int>();
         int ans = k, k1 = k, k2 = k;
         do {
             k1 = next(n, k1);
             k2 = next(n, k2); ans = std::max(ans, k2);
             k2 = next(n, k2); ans = std::max(ans, k2);
         }while(k1 != k2);
         printf("%d\n", ans);
     }

     return ;
 }