http://acm.hdu.edu.cn/showproblem.php?pid=5187
这道题普通的快速幂过不去,得用到快速乘的快速幂优化
直接贴代码
ll p;
ll mul(ll a, ll b) {
ll ans = 0;
while(b) {
if(b & 1) ans = (ans + a ) % p;
b >>= 1;
a = (a + a) % p;
}
return ans;
}
ll pow(ll a, ll b) {
ll res = 1;
ll base = a;
while(b) {
if(b & 1) res = mul(res, base) % p;
base = mul(base, base) % p;
b >>= 1;
}
return res;
}