You can easily write your own function using comparison operators such as >, <, >=, <=, and ==.

Here is an example from this site:

#include <stdio.h>

int main()
{
  int a, b;
  scanf("%d %d", &a, &b);//get two int values from user

  if (a < b)//is a less than b?
    printf("%d is less than %d\n", a, b);

  if (a == b)//is a equal to b?
    printf("%d is equal to %d\n", a, b);

  if (a > b)//is a greater than b?
    printf("%d is greater than %d\n", a, b);

  return 0;
}

You can use this knowledge to do a simple function that follows this pseudo code:

//get a and b int variable
//is a greater than or equal to b?
    //return a
//else
    //return b

Some other useful resources:

http://c.comsci.us/tutorial/icomp.html

http://www.cyberciti.biz/faq/if-else-statement-in-c-program/