C programming, a answer as quickly as possible would be much appreciated. thanks in before hand

Sometimes we talk about editing distances between two strings. That's how many changes one needs to do for one string to become the other string. In this case we limit ourselves to strings of the same length and define the editing distance as how many characters you have to replace in order for one to become the other. For example, is the editing distance between 'fyra' and 'mura' 2, while the editing distance between 'fyra' and 'myra' is 1. The distance between 'fyra' and 'fary', on the other hand, is 2. a) Write a C function int difference (const char * str1, const char * str2) which calculates this type of editing distance, given two strings as input. You can use the strlen function to check the length of a string, and you can assume that both strings are the same length