@[okkkkkkkkk](/user/1035639) 我也是用函数但是类型是int
```
#include<bits/stdc++.h>
using namespace std;
int a(int j)
{
int flag=0;
for(int i=2;i<=sqrt(j);i++)
if(j%i==0)
flag=1;
return flag;
}
int main()
{
int n;
cin>>n;
cout<<4<<"="<<2<<"+"<<2<<endl;
for(int i=6;i<=n;i+=2)
{
for(int j=3;j<=i;j+=2)
{
int flag=0;
flag+=a(j);
flag+=a(i-j);
if(flag==0)
{
cout<<i<<"="<<j<<"+"<<i-j<<endl;
break;
}
}
}
return 0;
}
```
by x1489631649 @ 2023-07-21 09:24:48
@[okkkkkkkkk](/user/1035639) n=4单独写是因为4以后的数不会含有因数2然后直接两个两个加上去
by x1489631649 @ 2023-07-21 09:27:54
谢谢！
by sans_001 @ 2023-07-21 09:35:00
新代码终于过了
```cpp
#include <bits/stdc++.h>
using namespace std;
bool zhishu(int a) {
for (int i = 2; i <= sqrt(a); i++) {
if (a % i == 0) {
return false;
}
}
return true;
}
int main() {
int n;
cin >> n;
cout << "4=2+2" << endl;
for (int k = 6; k <= n; k += 2) {
for (int i = 2; i <= k; i++) {
if (zhishu(i) && zhishu(k - i)) {
cout << k << "=" << i << "+" << k - i << endl;
break;
}
}
}
return 0;
}
```
by sans_001 @ 2023-07-21 09:35:53