C++ 解法, 执行用时: 115ms, 内存消耗: 10204K, 提交时间: 2021-10-15 19:15:19

#include<bits/stdc++.h>
using namespace std;
#define For(i,x,y)for(i=x;i<=(y);i++)
const int LIM=10000000;
bool p[10000005];
int main()
{
	int t,i,j,s;
	cin>>t;
	For(i,2,LIM)
	if(!p[i])
	for(j=i+i;j<=LIM;j+=i)p[j]=1;
	while(t--)
	{
		cin>>s;
		if(s<4||!p[s])cout<<1<<endl<<s<<" = "<<s<<endl;
		else if(!p[s-2])cout<<2<<endl<<2<<" + "<<s-2<<" = "<<s<<endl;
		else if(!(s&1))
		{
			cout<<2<<endl;
			For(i,2,s)
			if(!p[i]&&!p[s-i])break;
			cout<<i<<" + "<<s-i<<" = "<<s<<endl;
		}
		else
		{
			cout<<3<<endl<<1<<" + ";
			For(i,2,s-1)
			if(!p[i]&&!p[s-1-i])break;
			cout<<i<<" + "<<s-1-i<<" = "<<s<<endl;
		}
	}
	return 0;
}