SDE - 1

Given an integer ‘N’ representing the number of pairs of parentheses, Find all the possible combinations of balanced parentheses with the given number of pairs of parentheses.

Note :

Conditions for valid parentheses:
1. All open brackets must be closed by the closing brackets.

2. Open brackets must be closed in the correct order.

For Example :

()()()() is a valid parentheses.
)()()( is not a valid parentheses.

Ninja is now bored with numbers and is now playing with characters but hates when he gets repeated characters. Ninja is provided a string, and he wants to return the first unique character in the string.The string will contain characters only from the English alphabet set, i.e., ('A' - 'Z') and ('a' - 'z'). If there is no non-repeating character, print the first character of the string. If there is no non-repeating character, return the first character of the string.