Monkey Tradition---LightOj1319（中国剩余定理模板）

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<stdlib.h>

#define MAXN 22
typedef long long LL;

void ex_gcd(LL a, LL b, LL &x, LL &y)
{
if(b==0)
{
x = 1;
y = 0;
return ;
}
ex_gcd(b, a%b, x, y);
LL temp = x;
x = y;
y = temp - a/b * y;
if(a*b<0)
{
x = -x;
y = -y;
}
}
int main()
{
LL  A[MAXN], R[MAXN], N0, N[MAXN];

int n, T, t = 1;

scanf("%d", &T);

while(T--)
{
scanf("%d", &n);

memset(A, 0, sizeof(A));
memset(R, 0, sizeof(R));
memset(N, 0, sizeof(N));

N0 = 1;

for(int i=1; i<=n; i++)
{
scanf("%lld %lld", &A[i], &R[i]);
N0 *= A[i];
}

LL x = 0;

for(int i=1; i<=n; i++)
{
LL K, K0;

ex_gcd(N0/A[i], -A[i], K, K0);

N[i] = A[i] * K0 + 1; ///或者 N[i] = N0/A[i] * K;

x = (x + N[i] * R[i] + N0) % N0;
}
printf("Case %d: %lld\n", t++, (x+N0)%N0);
}
return 0;
}