PAT Level B-String A+B

Problem description Given two strings A and B, this problem requires you to output A+B, which is the union of the two strings.

It is required to output A first and then B, but repeated characters must be eliminated.

Input format
input respectively given in two rows A and B, both the length of not more than 10 ^{. 6} is, seen from the ASCII characters and spaces, identified by the end of the transport of non-empty string.

Output format
Output the sum of A and B required by the title in one line.

输入样例
This is a sample test
to show you_How it works

Output sample
This ampletowyu_Hrk

---

answer:

#include <iostream>
using namespace std;

string s, a, b;
bool used[150];

int main()
{
    
    
	getline(cin, a);
	getline(cin, b);
	
	s = a + b;		
	for (int i = 0; i < s.size(); i ++)
		if(!used[s[i]])
		{
    
    
			cout << s[i];
			used[s[i]] = true;
		}	
		
	return 0;	
}