CRT模板

用于求解线性同余方程组。

查看代码

#include <iostream>
#include <cstdio>
using namespace std;
typedef long long LL;
const int N = 10;
int n;
LL res, mul = 1, A[N], B[N];
LL exgcd (LL a, LL b, LL& x, LL& y)
{
    if (!b)
    {
        x = 1, y = 0;
        return a;
    }
    LL d = exgcd(b, a % b, y, x);
    y -= a / b * x;
    return d;
}
LL inv (LL a, LL b)
{
    LL x, y;
    exgcd(a, b, x, y);
    return (x % b + b) % b;
}
int main ()
{
    
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> A[i] >> B[i];
        mul *= A[i];
    }
    for (int i = 0; i < n; i++)
        res = (res + B[i] * (mul / A[i]) % mul * inv(mul / A[i], A[i]) % mul) % mul;
    cout << res;
    return 0;
}