C Program to Find Substring Of String Without Using Library Function

C Program to Find Substring Of String Without Using Library Function 

#include<stdio.h>
#include<string.h>

int search(char[], char[]);

int main() {
   int loc;

   char source[] = "maharashtra";
   char target[] = "sht";

   loc = search(source, target);

   if (loc == -1)
      printf("\nNot found");
   else
      printf("\nFound at location %d", loc + 1);

   return (0);
}

int search(char src[], char str[]) {
   int i, j, firstOcc;
   i = 0, j = 0;

   while (src[i] != '\0') {

      while (src[i] != str[0] && src[i] != '\0')
         i++;

      if (src[i] == '\0')
         return (-1);

      firstOcc = i;

      while (src[i] == str[j] && src[i] != '\0' && str[j] != '\0') {
         i++;
         j++;
      }

      if (str[j] == '\0')
         return (firstOcc);
      if (src[i] == '\0')
         return (-1);

      i = firstOcc + 1;
      j = 0;
   }
}