Trie is usually used to implement dictionary since the complexity of finding a particular word from given dictionary words is O(L) where L is the length of the word.

Give a good data structure for having n queues (n not fixed) in a finite memory segment. You can have some data-structure separate for each queue. Try to use at least 90% of the memory space.

Which data structure will be best for storing very large numbers (for example a number having 10^3 digits). Additionally, I want to perform comparison operation on them..

Given a dictionary of strings and another string find out if the string is an exact match to some words in the dictionary or varies at most in only one place of some word of the dictionary?

Given a string and dictionary of words, form a word by removing minimum number of characters. Characters can be removed in-order only.