/**
 * Brute force string search
 * Noting really special going on here
 * **/


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

#ifndef NULL
#define NULL (void *)0
#endif

/**
 * A struct to keeps together search results
 * Not really much of an arraylist
 * **/
typedef struct  {
    int count;
    int array[100];
} arrayList; 

/**
 * Print the found locations
 * @param al -- an array list instance
 * **/
void printList(arrayList* al) {
    for (int i = 0; i < al->count; i++)
        printf("%d\n", al->array[i]);
}

/**
 * Return true if needle and stackpart are the same
 * @param needle -- a string
 * @param stackpart -- the other stirng
 * @return true iff needle and stackpart are the same
 * **/
int compare(char *needle, char *stackpart) {
    while (*needle && *stackpart)
    {
        if (*needle != *stackpart) {
            return 0;
        }
 
        needle++;
        stackpart++;
    }
    return (*needle == '\0');
}
 
/**
 * My implementation of the library strstr function
 * @param needle -- a string
 * @param stackpart -- the other stirng
 * @return true iff needle and stackpart are the same
 * **/
int strstrGT(char* needle, char* haystack) {
    int hayloc = 0;
    //printf("%s  %s\n", needle, haystack);
    while (*haystack != '\0')
    {
        if ((*needle == *haystack) && compare(needle, haystack)) {
            //printf("     %d\n", hayloc);
            return hayloc;
        }
        haystack++;
        hayloc++;
    }
    //printf("NF\n");
    return -1;
}
 
 /**
  * Find every instance of needle within haystack
  * @param needle -- a string
 * @param stackpart -- the other stirng
 * @return arrayList instance containing location of all matches
 * **/
arrayList allLocsF(char* needle, char* haystack) {
    arrayList ret = (arrayList){.count = 0};
    int oloc = 0;
    int nloc;
    while (0 <= (nloc = strstrGT(needle, haystack + oloc)))
    {
        ret.array[ret.count++] = nloc+oloc;
        oloc = oloc + nloc + 1;
    }
    return ret;
}

/**
 * Make a string of the given length
 * @param len -- the length of the string to be created
 * @return a pointer to a block of memory of the given size which was malloc'd
 * **/
char* makeString(long len) {
    char *aa = malloc((len + 1) * sizeof(char));
    for (int i = 0; i < len; i++)
        aa[i] = 'a' + (rand() % 26);
    aa[len] = '\0';
    return aa;
}

int main(int argc, char const *argv[])
{
    srand(time(NULL));
    char *haystack = makeString(atol(argv[2]));
    int cou = atoi(argv[3]);
    for (int i = 0; i < cou; i++) {
        char *needle = makeString(atol(argv[1]));
        arrayList allLocs = allLocsF(needle, haystack);
        printList(&allLocs);
        free(needle);
    }
    free(haystack);
    return 0;
}