Please solve for C

Write a program that encodes the input characters using the following algorithm. - if the input character is a digit ('0' through '9'), then output the digit by adding 6 to the digit and calculate the remainder by 10 . For example, if a digit is ' 6 ', then replaced digit is ' 2 '. Subtract the digit with ' 0 ', add 6 , and then calculate the remainder by 10 , then add ' 0 '. - If the character is an alphabetic letter, then shift the letter by 6. For example, if the letter is ' B ', then the letter becomes 'H'. Subtract the letter with 'a' (for lower case) or 'A' (for uppder case), add 6, and then calculate the remainder by 26, then add 'a' (for lower case) or 'A' (for uppder case). For example, 'X' shifted by 6 is 'D'. - If the character is a white space, skip it. - If the character is not a digit, an alphabetic letter, or a white space, output the underscore ' ' character. Requirements 1. Follow the format of the examples below. 2. Use getchar() function to read in the input. Do not use scanf. 3. The user input ends with the user pressing the enter key (a new line character). 4. Character handling library functions in ctype.h are allowed