Design a C program for following functions.

(a). Create a STACK structure for storing one character in each location of the stack. Write supporting functions for stack operations like push, pop etc. Memory is to be allocated dynamically using malloc ().

(b). Design a function to accept character string as input. The string is inputted using a pointer to a character. The individual characters of the string are extracted and stored in the STACK.

(c). Now the STACK is sorted and all multiple occurrences of a character is deleted from the stack.

(d). Finally the contents of STACK are used to create a result string using pointer to character. .