The interleaving of two strings x and y is a string that contains all characters of x and y and preserves the relative order of the characters in both x and y. For example, the interleaving of abc and xyz is axbycz. Write a program that prints the interleaving of every given pair of strings.
Define and use a recursive function
that returns the interleaving of two strings x and y.
Input
The input consists of several pairs of strings.
Output
Print the interleaving of every given pair of strings.
Input
abc xyz ab xyz abc xy
Output
axbycz axbyz axbyc