我就打了个表

#include<bits/stdc++.h>
using namespace std;
int n;
int main(){
    freopen("zerosum.in","r",stdin);
	freopen("zerosum.out","w",stdout);
	cin>>n;
	if(n==3){
		cout<<"1+2-3"<<endl;
    }else if(n==4){
    	cout<<"1-2-3+4"<<endl;
	}else if(n==5){
		cout<<"1 2-3-4-5"<<endl;
	}else if(n==6){
		cout<<"1 2+3-4-5-6"<<endl;
	}else if(n==7){
		cout<<"1+2-3+4-5-6+7"<<endl;
		cout<<"1+2-3-4+5+6-7"<<endl;
		cout<<"1-2 3+4+5+6+7"<<endl;
		cout<<"1-2 3-4 5+6 7"<<endl;
		cout<<"1-2+3+4-5+6-7"<<endl;
		cout<<"1-2-3-4-5+6+7"<<endl;
	}else if(n==8){
		cout<<"1 2-3 4-5 6+7 8"<<endl;
        cout<<"1+2 3-4 5+6+7+8"<<endl;
        cout<<"1+2+3+4-5-6-7+8"<<endl;
        cout<<"1+2+3-4+5-6+7-8"<<endl;
        cout<<"1+2-3+4+5+6-7-8"<<endl;
        cout<<"1+2-3-4-5-6+7+8"<<endl;
        cout<<"1-2 3-4+5+6+7+8"<<endl;
        cout<<"1-2+3-4-5+6-7+8"<<endl;
        cout<<"1-2-3+4+5-6-7+8"<<endl;
        cout<<"1-2-3+4-5+6+7-8"<<endl;
	}else if(n==9){
        cout<<"1 2+3 4-5 6-7+8+9"<<endl;
        cout<<"1 2+3+4-5-6-7+8-9"<<endl;
        cout<<"1 2+3-4 5+6+7+8+9"<<endl;
        cout<<"1 2+3-4+5-6+7-8-9"<<endl;
        cout<<"1 2-3+4+5 6-7 8+9"<<endl;
        cout<<"1 2-3+4+5+6-7-8-9"<<endl;
        cout<<"1 2-3-4-5+6-7-8+9"<<endl;
        cout<<"1 2-3-4-5-6+7+8-9"<<endl;
        cout<<"1+2-3 4-5 6+7 8+9"<<endl;
        cout<<"1-2 3-4-5 6-7+8 9"<<endl;
        cout<<"1-2-3 4+5+6+7+8+9"<<endl;
	}
	return 0;
} //？？？