More Problems

• Write a program to find the sum of all digits in a number using recursion.
• Write a program to convert a string of digits into an integer without using atoi.
• Write a program to check if a number is a happy number using a function.
• Write a program to find the total number of uppercase letters in a string.
• Write a program to implement a simple address book with file storage.
• Write a program to check if a number is a perfect cube using a function.
• Write a program to find the longest common prefix among a list of strings.
• Write a program to calculate the area of a circle given its radius.