快速幂模板
例题
long long qpow(long long a,long long b) { long long res = 1 % mod; while(b) { if(b & 1) res = (res * a) % mod; a = a * a % mod; b >>= 1; } return res; }
快速乘模板
[例题](https://www.acwing.com/problem/content/92/) ```c++ long long qmul(long long a,long long b) { long long res = 0; while(b) { if(b & 1) res = (res + a) % mod; a = a * 2 % mod; b >>= 1; } return res; }