More Problems

• Write a program to check if a string is a valid date in the format YYYY/MM/DD.
• Write a program to find the first unique character in a string with the least number of appearances.
• Write a program to implement a basic online food ordering system.
• Write a program to check if a number is a Fibonacci number using dynamic programming.
• Write a program to find the longest substring of unique characters using a sliding window technique.
• Write a program to implement a simple online bookstore with inventory management.
• Write a program to check if a binary tree is a valid AVL tree.
• Write a program to find the longest palindromic substring using the expanding window technique.