Find the frequency of "the" in the given string

Given a string , find the number of times the word "the" occurs in the string.



#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(void) {

    /* Initialize the word "the", substring, the count of which is extracted from the main string s */
  char *s,*v="the";

   int slen,i,index,j,k,flag,count=0;

    /* Allocate memory for the input string */
  s=(char*)malloc(sizeof(s)*256);

    /* Get the input string from the user */
  scanf("%s",s);

    /* Calculate the length of the input string (number of characters except '\0'(null character)) */
  slen=strlen(s);

    /* Until we reach the end of the string */
  for(i=0;i<slen;i++)
   {
                     
     /* Set the flag value to 1 */
    flag=1;

        /* Compare the first character occurence of the first character from the substring "the" in main string */
    if(*(s+i)==*v)
     {

         /* If the first character of both the string matches */
      k=i;

            /* Until we reach the end of the sub-string "the" , check if all the characters of it matches with the characters of the main string from that index */
      for(j=0;*(v+j);j++,k++)
      {
             /* If any of the character in the sub-string doesn't match the characters in the main string , set the flag value as 0(zero) */
       if(*(s+k)!=*(v+j))
        {
          flag=0;
          break;
        }
      }

         /* If the flag value is not set , then there exists atleast one substring that matches in the main string */
     if(flag)
     {
         /* Increment the count of the sub-string occurence all the characters of sub-string matches a part of the main string */
      count++;
     }
    }
  }

    /* Print the count of the occurence of the word "the" in the main string */
  printf("count of 'the' in %s is %d",s,count);
   return 0;
}