More Problems

• Write a program to find the first unique character in a string with the least appearances.
• Write a program to implement a basic text-based simulation of a banking system.
• Write a program to check if a string is a valid XML document.
• Write a program to find the maximum sum of any two numbers in an array.
• Write a program to check if a string is a valid email address format.
• Write a program to find the longest sequence of repeating characters in a string.
• Write a program to implement a simple online quiz application with timed questions.
• Write a program to check if a number is a Fibonacci number using a closed formula.