the solution to the usaco problem Longest prefix
File list:
Longest Prefix
.............\bin
.............\...\Debug
.............\...\.....\Longest Prefix.exe
.............\obj
.............\...\Debug
.............\...\.....\main.o
.............\Longest Prefix.cbp
.............\Longest Prefix.depend
.............\Longest Prefix.layout
.............\main.cpp
.............\prefix.in
.............\prefix.out