UVa #11582 Colossal Fibonacci Numbers! (例题10-1)

预处理求出n分别为1-1000时斐波那契模数列的周期，之后求出a^b是周期中第几个即可。

复习了模算术、幂取模，顺便学习了分治法取模的迭代版本。

Run Time: 0.072s

#define UVa  "LT10-1.11582.cpp"//Colossal Fibonacci Numbers!char fileIn[30] = UVa, fileOut[30] = UVa;#include<cstring>#include<cstdio>#include<algorithm>using namespace std;//Global Variables. Reset upon Each Case!typedef unsigned long long ULL;const int maxn = 1000 + 5;int m[maxn];unsigned long long f[maxn][3100];unsigned long long a,b;int n;/////int power(ULL a, ULL b, int t) {    ULL result = 1;    while(b) {        if(b%2) {            result = (a*result)%t;        }        a = (a*a)%t;        b/=2;    }    return result;}int main() {    for(n = 2; n <= 1000; n ++) {        int tmp = 0;        f[n][0] = 0, f[n][1] = 1;        for(int i = 2; ; i ++) {            f[n][i] = (f[n][i-2]%n + f[n][i-1]%n) % n;            if(f[n][i] == 1 && f[n][i-1] == 0) {                m[n] = i-1;                break;            }        }    }    int T;    scanf("%d", &T);    while(T--) {        scanf("%llu%llu%d", &a, &b, &n);        if(a == 0 || n == 1) printf("0\n");        else printf("%d\n", f[n][power(a%m[n], b, m[n])]);    }    return 0;}