hdu 1370 Biorhythms

中国剩余定理……、

链接http://acm.hdu.edu.cn/showproblem.php?pid=1370

/*************************************************************************
    > File Name: xh.cpp
    > Author: XINHUA
    > Mail: 525799145@qq.com 
    > Created Time: 2013/7/11 星期四 17:46:00 新华
 ************************************************************************/

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<iomanip>
using namespace std;
int extend_gcd(int a,int b,int &x,int &y)
{
    int m;
    if(b==0)
    {
        x=1;y=0;
        return a;
    }
    else
    {
        m=extend_gcd(b,a%b,x,y);
        int c=x;
        x=y;
        y=c-a/b*(y);
    }
    return m;
}
int mod(int a,int m)
{
    int x,y,gcd;
    gcd=extend_gcd(a,m,x,y);
    if(gcd==1)
    {
        if(x<0)
            x=(x%m+m)%m;
        return x;
    }
    else return 0;
}
int china(int m0[],int b[],int d)
{
    int x,y,n,m=1,a=-d;
    int i;
    for(i=0;i<3;i++) m*=m0[i];
    for(i=0;i<3;i++)
    {
        n=m/m0[i];
        extend_gcd(n,m0[i],x,y);
        a=a+n*b[i]*x;
    }
    return a%m;
}
int main()
{
    int p,e,i,d,k,sum,l=0,m[3]={
        23,28,33
    },b[3];
    char c;
    cin>>c;
    while(cin>>p>>e>>i>>d)
    {
        if(p==-1&&e==-1&&i==-1&&d==-1)
            break;
        b[0]=p;b[1]=e;b[2]=i;
        sum=china(m,b,d);
        if(sum<=0) sum+=21252;
        printf("Case %d: the next triple peak occurs in %d days.
",++l,sum);
    }
    return 0;
}