UVa 11582 - Colossal Fibonacci Numbers!
数学题,寻找斐波那契取模后的周期T,然后求Mod_Fib(a^b % T)即可。
求a^b % T时要用快速幂来计算,详细方法为http://blog.csdn.net/kun768/article/details/42344897
#include <cstdio> #include <iostream> using LLU = unsigned long long; using namespace std; int Fib[1024000]; int init(const int n) { Fib[0] = 0, Fib[1] = 1; for (int i = 2;; ++i){ Fib[i] = (Fib[i - 1] + Fib[i - 2]) % n; if (Fib[i] == 1 && Fib[i - 1] == 0) return i - 1; } } int Pow(LLU a, LLU b, int Base){ LLU res = 1; LLU t = a; while (b > 0) { if (b % 2) res = (res * t) % Base; t = (t * t) % Base; b >>= 1; } return (int)res; } int main() { int T; cin >> T; while (T--) { LLU a, b; int n; cin >> a >> b >> n; if (n == 1) { puts("0"); continue; } int Base = init(n); cout << Fib[Pow(a % Base, b, Base)] << endl; } return 0; }