acm:a^b%p-number theory-fast power-fast multiplication

A^b

Time Limit: 1000MS

Memory Limit: 65535KB

64bit IO Format:

Description

Ask for A's B-square, modulo mod (1<=a,b,mod<=1e18)

Input

Multiple sets of inputs, one row per set of data, 3 positive integers, respectively a,b,mod

Output

One row for each set of data output, for the answer

Sample Input

2 10 100000005 100 10 2 37

Sample Output

102400


Template problem, mainly considering the 1e18 of the huge, ordinary fast power will explode ll so in the place of multiplication with the fast multiply, avoid the burst LL.

#include "Cstdio" Long long Mod_mul (long long A,long long B,long long) {Long long r=0;long long t=a; while (b) {if (b&1) R= (r+t)%p;t= (t<<1)%p;b>>=1;} return r;} Long Long Mod_pro (long long A,long long B,long long p) {Long long r=1;long long t=a; while (b) {if (b&1) R=mod_mul (r,t,p )%p;t=mod_mul (t,t,p)%p;b>>=1;} return r;} int main () {Long Long a,b,mod;while (~scanf ("%i64d%i64d%i64d", &a,&b,&mod)) {printf ("%i64d\n", Mod_pro (A, B , MoD));} return 0;}

　　

acm:a^b%p-number theory-fast power-fast multiplication