Здравейте, уж я реших задачата, но явно съм пропуснал нещо в кода и един тест не минава. Това е линкът към джъдж -> https://judge.softuni.bg/Contests/Compete/Index/321#4, а това е линкът към проблемния код -> http://pastebin.com/wjLaSRge.

За да не търсите условието ще го пейстна тук:

"Write a method that takes as input two strings, and returns Boolean if they are exchangeable or not. Exchangeable are words where the characters in the first string can be replaced to get the second string. Example: "egg" and "add" are exchangeable, but "aabbccbb" and "nnooppzz" are not. (First 'b' corresponds to 'o', but then it also corresponds to 'z'). The two words may not have the same length, if such is the case they are exchangeable only if the longer one doesn't have more types of characters then the shorter one ("Clint" and "Eastwaat" are exchangeable because 'a' and 't' are already mapped as 'l' and 'n', but "Clint" and "Eastwood" aren't exchangeable because 'o' and 'd' are not contained in "Clint")."

Ще съм много благодарен на човека решил да помогне малко.