Question:http://poj.org/problem?id=1006
问题点:孙子定理
1 Memory: 248K Time: 0MS
2 Language: C++ Result: Accepted
3
4 #include <iostream>
5
6 using namespace std;
7 int getGCD(int a,int b)//Greatest Common Divisor
8 {
9 if(a<b){a+=b;b=a-b;a=a-b;}
10 if(b==1) return 1;
11 else if(a%b==0) return a/b;
12 else return getGCD(b,a%b);
13 }
14 int getLCM(int a,int b)//Lowest Common Multiple
15 {
16 return a*b/getGCD(a,b);
17 }
18 int getMod1(int a,int b)//get N. a*N mod b ==1
19 {
20 int N=0;
21 while(a*N%b!=1){N++;}
22 return a*N;
23 }
24 int main()
25 {
26 int p,e,i,d,cnt=1;
27 int pe=getMod1(getLCM(23,28),33);
28 int pi=getMod1(getLCM(23,33),28);
29 int ei=getMod1(getLCM(28,33),23);
30 while(true)
31 {
32 cin>>p>>e>>i>>d;
33 if(p==-1&&e==-1&&i==-1&&d==-1) return 0;
34 int m=(ei*p+pi*e+pe*i)%(23*28*33)-d;
35 if(m<=0) m+=23*28*33;
36 cout<<"Case "<<cnt++<<": the next triple peak occurs in "<<m<<" days."<<endl;
37 }
38 }