More Problems

• Write a program to check if a string is a valid hexadecimal color code.
• Write a program to find the sum of the first n odd prime numbers.
• Write a program to implement a simple feedback collection system.
• Write a program to check if a given string is a valid IPv4 address.
• Write a program to find the longest word in a text file.
• Write a program to calculate the number of vowels in a given file.
• Write a program to implement a basic grade calculator with letter grades.
• Write a program to check if a number is a perfect number using its divisors.