oji | Text Emoticons Maker | Icon library

I am trying to output all the file names in a directory to a file. Seems simple, but in the future I will be creating useful information based off the file names and outputting to a file for another system.

When I output the information to a file it shows as gibberish when I open in notepad. Outputting to the screen looks fine.

Here is my code:

I've just installed gnupg pecl extension and required libraries, gnupg seems to be enabled in my phpinfo();

php -i | grep gnupg

*Sorry about my poor English. If there is anything that you don't understand, please tell me so that I can give you more information that 'make sence'.

**This is first time asking question in Stackoverflow. I've searched some rules for asking questions correctly here, but there should be something I missed. I welcome all feedback.

I'm currently solving algorithm problems to improve my skill, and I'm struggling with one question for three days. This question is from https://algospot.com/judge/problem/read/RESTORE , but since this page is in KOREAN, I tried to translate it in English.

Question
If there are 'k' pieces of partial strings given, calculate shortest string that includes all partial strings. All strings consist only lowercase alphabets. If there are more than 1 result strings that satisfy all conditions with same length, choose any string.

Input
In the first line of input, number of test case 'C'(C<=50) is given. For each test case, number of partial string 'k'(1<=k<=15) is given in the first line, and in next k lines partial strings are given. Length of partial string is between 1 to 40.

Output
For each testcase, print shortest string that includes all partial strings.

Sample Input
3
3
geo
oji
jing
2
world
hello
3
abrac
cadabra
dabr

Sample Output
geojing
helloworld
cadabrac

And here is my code. My code seems to work perfect with Sample Inputs, and when I made test inputs for my own and tested, everything worked fine. But when I submit this code, they say my code is 'wrong'.

Please tell me what is wrong with my code. You don't need to tell me whole fixed code, I just need sample inputs that causes error with my code. Added code description to make my code easier to understand.

Code Description

Saved all input partial strings in vector 'stringParts'.
Saved current shortest string result in global variable 'answer'.
Used 'cache' array for memoization - to skip repeated function call.

Algorithm I designed to solve this problem is divided into two function - restore() & eraseOverlapped().

restore() function calculates shortest string that includes all partial strings in 'stringParts'.
Result of resotre() is saved in 'answer'.

For restore(), there are three parameters - 'curString', 'selected' and 'last'.
'curString' stands for currently selected and overlapped string result.
'selected' stands for currently selected elements of 'stringParts'. Used bitmask to make my algorithm concise.
'last' stands for last selected element of 'stringParts' for making 'curString'.

eraseOverlapped() function does preprocessing - it deletes elements of 'stringParts' that can be completly included to other elements before executing restore().