More Problems

• Write a program to check if a binary tree is a valid binary search tree.
• Write a program to find the total number of unique characters in a string.
• Write a program to implement a basic online file sharing service.
• Write a program to check if a string contains only balanced parentheses.
• Write a program to find the first character that is not repeated in a string.
• Write a program to implement the counting sort algorithm.
• Write a program to check if a number can be expressed as a sum of two squares.
• Write a program to find the maximum length of a palindromic substring in a string.