use of strstr in c 2b 2b

1#include <iostream>
2#include <string.h>
3
4using namespace std;
5int main() {
6   char str1[] = "Apples are red";
7   char str2[] = "are";
8   char *ptr;
9   ptr = strstr(str1, str2);
10
11   if(ptr)
12   cout<<"Occurance of \""<< str2 <<"\" in \""<< str1 <<"\" is at position "<<ptr - str1 + 1;
13
14   else
15   cout<<"There is no occurance of \""<< str2 <<"\" in "<<str1;
16   return 0;
17}

1/* strstr example */
2#include <stdio.h>
3#include <string.h>
4
5int main ()
6{
7  char str[] ="This is a simple string";
8  char * pch;
9  pch = strstr (str,"simple");
10  strncpy (pch,"sample",6);
11  puts (str);
12  return 0;
13}