1367A - Short Substrings.cpp

/*
Alice guesses the strings that Bob made for her.

At first, Bob came up with the secret string a consisting of lowercase English letters. The string a has a length of 2 or more characters. Then, from string a he builds a new string b and offers Alice the string b so that she can guess the string a.

Bob builds b from a as follows: he writes all the substrings of length 2 of the string a in the order from left to right, and then joins them in the same order into the string b.

For example, if Bob came up with the string a="abac", then all the substrings of length 2 of the string a are: "ab", "ba", "ac". Therefore, the string b="abbaac".

You are given the string b. Help Alice to guess the string a that Bob came up with. It is guaranteed that b was built according to the algorithm given above. It can be proved that the answer to the problem is unique.

Input
The first line contains a single positive integer t (1=t=1000) — the number of test cases in the test. Then t test cases follow.

Each test case consists of one line in which the string b is written, consisting of lowercase English letters (2=|b|=100) — the string Bob came up with, where |b| is the length of the string b. It is guaranteed that b was built according to the algorithm given above.

Output
Output t answers to test cases. Each answer is the secret string a, consisting of lowercase English letters, that Bob came up with.

Example
inputCopy
4
abbaac
ac
bccddaaf
zzzzzzzzzz
outputCopy
abac
ac
bcdaf
zzzzzz
Note
The first test case is explained in the statement.

In the second test case, Bob came up with the string a="ac", the string a has a length 2, so the string b is equal to the string a.

In the third test case, Bob came up with the string a="bcdaf", substrings of length 2 of string a are: "bc", "cd", "da", "af", so the string b="bccddaaf"
*/


#include<bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    
    int t;
    cin >> t;
    
    while (t--) {
    	string b;
    	cin >> b;
    	
    	string a = "";
    	
    	a += b[0];
    	
    	int n = b.length();
    	
    	for (int i = 1; i < n - 1; i+=2) {
    		a += b[i];
		}
		
		a += b[n - 1];
		
		cout << a << endl;
	}
    
    return 0;
}