Check whether the string contains substrings in C language

/*
Example: Testing if a string is found or not in C language
*/

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

int main()
{
    char s1[] = "hello lautturi world";
    char s2[] = "idea";
    char* p;

    p = strstr(s1, s2);

    if (p) {
        printf("String found :%s \n",p);
    } else
        printf("String not found\n");

    return 0;
}