int substring(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 (0);

        firstOcc = i;

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

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

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