题解

#include<bits/stdc++.h>
using namespace std;
int main(){
	int t;
	cin >> t;
    
	while(t--){
		int l, r;
		cin >> l >> r;
		int luckymun = 0, flag =1, ans;        
		for(int i = l; i <= r; i++){
			int m = i, Max = 0, Min = 9;
			while(m!=0){
				Max = max(Max, m%10);
				Min = min(Min, m%10);
				m /= 10;
			}   
			if(luckymun < Max - Min) {
				luckymun = Max - Min;
				ans = i;
			}
			if(luckymun == 0 && Max - Min == 0) ans = i;       
			if(luckymun == 9){
				cout<< i << endl;
                flag=0;
				break; 
			}
		}
		if(flag != 0){
			cout << ans << endl;
		}		
	}
	return 0;
}