2805: Verifying mathematical conjectures.

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 234  Solved: 153
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Description

Write a program to verify Goldbach's conjecture: an even number not less than 6 can be expressed as the sum of two prime numbers. Submit the function prime .

Input

8

Output

8=5+3

HINT

#include <iostream>

#include <cmath>

using namespace std;

intmain()

{ int prime(int);

 int n,a,b;

 cin>>n;

 for(a=3;a<=n;a=a+2)

 { if(prime(a))

    { b=n-a ;

     

 if(prime(b))

cout<<n<<"="<<a<<"+"<<b<<endl;

}

 return 0;}

}

Source

tanzheng

Code:

#include <iostream>
#include <cmath>
using namespace std;
int main()
{ 
int prime(int);
  int n,a,b;
  cin>>n;
  for(a=3;a<=n;a=a+2)
  {if(prime(a)) {b=n-a ;if(prime(b))cout<<n<<"="<<a<<"+"<<b<<endl;}return 0;}}int prime(int n){int i,t;for(i=2;i<n;i++){if(n%i==0)return 0;}return 1;}