AcWing 887. 求组合数 III
原题链接
简单
作者:
芝居気
,
2021-12-17 14:28:08
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所有人可见
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#include<iostream>
using namespace std;
typedef long long LL;
int p;
int qpow(int a, int b)
{
int res = 1;
while (b)
{
if (b & 1) res = (LL)res * a % p;
a = (LL)a * a % p;
b >>= 1;
}
return res;
}
int C(int a, int b)
{
int res = 1;
for (int i = 1, j = a; i <= b; i++, j--)
{
res = (LL)res * j % p;
res = (LL)res * qpow(i, p - 2) % p;
}
return res;
}
int lucas(LL a, LL b)
{
if (a < p && b < p) return C(a, b);
return (LL)C(a % p, b % p) * lucas(a / p, b / p) % p;
}
int main()
{
int n;
cin >> n;
while (n--)
{
LL a, b;
cin >> a >> b >> p;
cout << lucas(a, b) << endl;
}
}