—————————————————————————————————

这题贪心我都过了，建议加强数据

#include<bits/stdc++.h>
using namespace std;
int t,n,x;
int main(){
	cin>>t;
	while(t--){
		cin>>x;int mm=x/7;
		if(x==1)cout<<-1;
		else if(x==2)cout<<1;
		else if(x==3)cout<<7;
		else if(x==4)cout<<4;
		else if(x==5)cout<<2;
		else if(x==6)cout<<6;
		else if(x%7==0){
			while(x>0)cout<<8,x-=7;
		}else if(x%7==1){
			cout<<10;x-=8;
			while(x>0)cout<<8,x-=7;
		}else if(x%7==2){
			cout<<1;x-=2;
			while(x>0)cout<<8,x-=7;
		}else if(x%7==3){
			if(x==10)cout<<22; 
			else {
				cout<<200;x-=17;
				while(x>0)cout<<8,x-=7;
			}
		}else if(x%7==4){
			cout<<20;x-=11;
			while(x>0)cout<<8,x-=7;
		}else if(x%7==5){
			cout<<28;x-=12;
			while(x>0)cout<<8,x-=7;
		}else if(x%7==6){
			cout<<6;x-=6;
			while(x>0)cout<<8,x-=7;
		} 
		cout<<"\n";
	}
	return 0;
}

我是**，不会写dp