B1029 old keyboard

1029 Old keyboard (20 branch )

Some keys on the old keyboard are broken , So when you type a paragraph , The corresponding character will not appear . Now give a paragraph of text that should be entered 、 And the text actually entered , Please list the keys that must be broken .

Input format ：
Enter in 2 Each line gives the text that should be entered 、 And the text actually entered . Each paragraph is no more than 80 Character string , By letter A-Z（ Including big 、 A lowercase letter ）、 Numbers 0-9、 And underline _（ On behalf of the space ） form . Title assurance 2 None of the strings are empty .

Output format ：
In the order of discovery , Output broken keys on one line . Only uppercase letters are output , Each bad key is output only once . The title is guaranteed to have at least 1 Bad key .

sample input

7_This_is_a_test
_hs_s_a_es

sample output

7TI

Topic analysis ：

1. Use toupper Function converts lowercase letters to large letters and saves all missing letters s3 in
2. Traverse s3 duplicate removal

The code is as follows ：

#include<bits/stdc++.h>
using namespace std;
int main(){
	string s1,s2,s3;
    cin>>s1>>s2;
	for(int i=0;i<s1.size();i++){
		if(s2.find(s1[i])==string::npos&&s2.find(toupper(s1[i]))==string::npos){
			s3+=toupper(s1[i]);//toupper Function to convert lowercase letters to uppercase letters 
		}
	}
	for(int i=0;i<s3.size();i++){
		string s=s3.substr(0,i);// Create string s3[0,i)
		if(s.find(s3[i])==string::npos){
			cout<<s3[i];
		}
	}
    // You can also use character arrays to store , Prioritize , After heavy unique(), Traversal up s3, Print in the original order 
	
	return 0;
}