ACM Pacific NW Region Programming Contest
13 November 2004
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Problem B
Zipper
Problem description
Given three strings, you are to determine whether the third string can be formed by
combining the characters in the first two strings. The first two strings can be mixed
arbitrarily, but each must stay in its original order.
For example, consider forming "tcraete" from "cat" and "tree":
String A: cat
String B: tree
String C: tcraete
As you can see, we can form the third string by alternating characters from the two
strings. As a second example, consider forming "catrtee" from "cat" and "tree":
String A: cat
String B: tree
String C: catrtee
Finally, notice that it is impossible to form "cttaree" from "cat" and "tree".
The Input (from file b.in)
The first line of input file, b.in, contains a single positive integer from 1 through
1000. It represents the number of data sets to follow. The processing for each data set
is identical. The data sets appear on the following lines, one data set per line.
For each data set, the line of input consists of three strings, separated by a single
space. All strings are composed of upper and lower case letters only. The length of the
third string is always the sum of the lengths of the first two strings. The first two strings
will have lengths between 1 and 200 characters, inclusive.
The Output (to stdout)
For each data set, print:
Data set n: yes
if the third string can be formed from the first two, or
Data set n: no
if it cannot. Of course n should be replaced by the data set number. See the sample
output below for an example.
