[poj1006]Biorhythms

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 #include<cstdlib>
 5 #include<cmath>
 6 #include<iostream>
 7 using namespace std;
 8 typedef long long ll;
 9 ll x,y,r[10],m[10],n=3;
10 ll extgcd(ll a,ll b,ll &x,ll &y){
11     ll d=a;
12     if(b)   d=extgcd(b,a%b,y,x),y-=a/b*x;
13     else  x=1,y=0;
14 }
15 ll inv(ll t,ll mod){ extgcd(t,mod,x,y);return (x+mod)%mod;}
16 ll crt(int n,ll *a,ll *m){
17     ll M=1,ret=0;
18     for(int i=0;i<n;i++) M*=m[i];
19     for(int i=0;i<n;i++){
20         ll w=M/m[i];
21         ret+=w*inv(w,m[i])*a[i];
22         ret%=M;
23     }
24     return (ret+M)%M;
25 }
26 int main(){
27     ll a,Case=1;
28     m[0]=23,m[1]=28,m[2]=33;
29     while(cin>>r[0]>>r[1]>>r[2]>>a){
30         if(a==-1&&r[0]==-1&&r[1]==-1&&r[2]==-1) break;
31         printf("Case %d: ",Case++);
32         ll tmp=23*28*33;
33         ll ans=((crt(3,r,m)-a)%tmp+tmp)%tmp;
34         if(ans==0) ans+=tmp;
35         printf("the next triple peak occurs in %lld days.\n",ans);
36     }
37 }