#include <iostream>
#include <string>
#include <cstring>
#define T_SIZE 1001
using namespace std;
char* string_merge(char *, char *);
int main()
{
int t;
cin >> t;
char *S1 = new char[T_SIZE];
char *S2 = new char[T_SIZE];
char *S3 = new char[T_SIZE];
for(int i=0; i<t; i++)
{
cin >> S1;
cin >> S2;
S3 = string_merge(S1, S2);
cout << S3 << endl;
}
delete [] S1;
delete [] S2;
delete [] S3;
return 0;
}
char* string_merge(char *str1, char *str2)
{
unsigned int str1_len = strlen(str1);
unsigned int str2_len = strlen(str2);
// cout << "str1_len= " << strlen(str1) << endl;
// cout << "str2_len= " << strlen(str2) << endl;
unsigned int nr;
if(str1_len <= str2_len)
nr = str1_len;
else
nr = str2_len;
// cout << "nr= " << nr << endl;
char *str_new = new char[nr];
unsigned int j, k;
j=0;
k=0;
for (int i=0; i<nr; i++)
{
if(i%2 == 0)
{
str_new[i] = str1[j];
j++;
}
else
{
str_new[i] = str2[k];
k++;
}
}
return str_new;
}
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