Find a string (C)

findstr.c

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

int main()
{
    char *haystack,*needle,*loc,*tmphay;
    int x;
    x = 0;

    haystack = (char*)malloc(sizeof(char) * 256);
    needle = (char*)malloc(sizeof(char) * 20);

    printf("Enter a string: ");
    gets(haystack);
    printf("Enter a string to find: ");
    gets(needle);

    tmphay = haystack;

    do
    {
        loc = strstr(tmphay,needle);

        if (loc != NULL)
        {
            if (x == 0)
                printf("String found at positions: ");

            printf("%lu ", (loc - haystack) + 1);
            x++;
        }

        tmphay = loc + 1;
    }
    while (loc != NULL);

    if (x == 0)
        printf("No string found.");

    free(haystack);
    free(needle);
    return 0;
}