Question

Suppose, for example, that some k which is an arbitrary number=2 k=2, then there is code in C:

int wordcomp(char *p, char *q) {
   int n = k;
   for ( ; *p == *q ; p++, q++) {
      if (  *p==0 && --n == 0 )
         return 0;
   }
   return *p - *q;  
}      

Please explain to me what this code does? Also, what does *p-*q mean? Also, how is it implemented in Java?

Answer 1

please explain me what does this code do?

It compares two words

also what means *p-*q?

It means, Tell me the value of char the pointer p is pointing to, and rest it to the char the pointer q is pointing to.

and also how implement it in java?

The *p-*q part? Here is it.

// char c
// char k
c - k;

If you mean the whole function, this could help you to get started:

int wordcomp( String sp, String sq) {
   int n = k; // I have no idea what is this for
   int pi = 0, qi = 0;
   for ( ; sp.charAt(pi) == sq.charAt(qi) ; pi++, qi++) {
      if (  sp.length()==pi && --n == 0 )
         return 0;
  }
  return sp.charAt(pi) - sq.charAt(qi);

You need to validate limits tough.