【poj1006-biorhythms】中国剩余定理

//poj1006
/*
x%23=a;
x%28=b;
x%33=c;
*/
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
using namespace std;

int tx,ty;
/*
void exgcd(int a,int b)
{
if(b==0) {tx=1,ty=0;return ;}
exgcd(b,a%b);
int x=ty,y=tx-(a/b)*ty;
tx=x;ty=y;
}
*/
int main()
{
freopen("a.in","r",stdin);
freopen("a.out","w",stdout);
int T=0;
while(1)
{
int a,b,c,d;
scanf("%d%d%d%d",&a,&b,&c,&d);
if(a==-1 && b==-1 && c==-1 && d==-1) return 0;
int x=6*a*28*33;
int y=-9*b*23*33;
int z=2*c*23*28;
int g=23*28*33;
int ans=(x+y+z)%g;
while(ans-d <= 0) ans+=g;
while(ans-d > g) ans-=g;
printf("Case %d: the next triple peak occurs in %d days.\n",++T,ans-d);
}
return 0;
}