Computer Programming

Write a program in C to check happy number entered by user using the concept of function with return type and no arguments [Hint: Happy number is a number for which the sum of the squares of the digits eventually equals 1. For example, 203 is happy because $2^{2} + 0^{2} + 3^{2} = 13$; $1^{2} + 3^{2} = 10$; $1^{2} + 0^{2} = 1$].