Returns whether the stack is empty.

Iterative function to insert string in a trie

Removes the element on top of the stack and returns that element.

Returns the next element in the iteration without advancing the iterator.

Dequeue an item from the queue

:type x: int :rtype: int

Inserts a word into the trie.

Converts strings to int, raises exception for non-int literals

Function to find and print longest substring without repeating characters.

Initialize the triangle object and add the first element

:type s: str :rtype: int

This function takes two sorted arrays and retuen the merged and sorted array.

Separetes elements of the equation from string to list. >>>segregate("(1+(4+5+2)-3)+(6+8)") ['(', '(', 1, '+', '(', 4, '+',

Returns if there is any word in the trie that starts with the given prefix.

checks if the array contains a duplicate :param arr: List[int] a list of numbers :return: True or False if it contains a dupl