More Problems

• Write a program to find the first character that occurs more than once in a string.
• Write a program to implement a basic online education platform.
• Write a program to check if a number is a happy number using a function.
• Write a program to calculate the factorial of a number using recursion.
• Write a program to find the intersection of two arrays.
• Write a program to check if a string is a valid IPv6 address.
• Write a program to find the sum of the first n perfect squares.
• Write a program to implement a simple email subscription system.