C :

#include<stdio.h> 
int suShu(int x){
	int i,c=0;
	for(i = 2;i <= x / 2;i++){
		if(x % i == 0){
			c++;
			break;
		}
	}
	
	return c;
	
}
void show(int n){
	int i;
	for(i = 2;i <= n / 2;i++){
		if(suShu(i) == 0 && suShu(n - i) == 0){
			printf("%d=%d+%d\n",n,i,n-i);
		}
	}
	
}

int main(){ 
	int n,i;
	scanf("%d",&n);
	for(i = 4;i <= n;i+=2){
		show(i);
	}
	return 0;
} 

C++ :

#include <iostream>
#include <cmath>
using namespace std;
//判断素数
bool sushu(int n){
	int i;
	bool r=true;
	for(i=2;i<=sqrt(n);i++){
		if(n%i==0){
			r=false;
			break;
		}
	}
	if(n<=1){
		r=false;
	}
	return r;
}

//将一个偶数拆成素数和的方案列出来
void chaifeng(int n){
	int i;
	for(i=2;i<=n/2;i++){
		if(sushu(i)==true&&sushu(n-i)==true){
			cout<<n<<"="<<i<<"+"<<(n-i)<<endl;
		}
	}
} 

//将4~n的每个偶数拆成素数和的方案列出来
void caixiang(int n){
	int i;
	for(i=4;i<=n;i=i+2){
		chaifeng(i); 
	}
}
int main(){
	int n;cin>>n;
	caixiang(n);
}

Python :

import math;
def suShu(n):
   f = True;
   for i in range(2,int(math.sqrt(n))+1):
          if n % i == 0:
               f = False;
               break;
   return f and n != 1;

def chaiFen(n):
  for i in range(2,n // 2+1):
      if suShu(i) and suShu(n - i ):
             print(n,end='=');
             print(i,end='+');
             print(n-i);


n = int(input());
for i in range(2,n+1,2):
    chaiFen(i)   ;