/*
Challenge 240

Task 2: Build Array
Submitted by: Mohammad S Anwar

You are given an array of integers.

Write a script to create an array such that new[i] = old[old[i]] where 0 <= i < new.length.
Example 1

Input: @int = (0, 2, 1, 5, 3, 4)
Output: (0, 1, 2, 4, 5, 3)

Example 2

Input: @int = (5, 0, 1, 2, 3, 4)
Output: (4, 5, 0, 1, 2, 3)
*/

#include "utarray.h"
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[]) {
    if (argc < 2) {
        fputs("Usage: ch-2 n n n ...\n", stderr);
        exit(EXIT_FAILURE);
    }

    UT_array* old;
    utarray_new(old, &ut_int_icd);

    UT_array* new;
    utarray_new(new, &ut_int_icd);

    // parse args
    for (int i = 1; i < argc; i++) {
        int n = atoi(argv[i]);
        utarray_push_back(old, &n);
    }

    // process
    for (size_t i = 0; i < utarray_len(old); i++) {
        int* old_p = (int*)utarray_eltptr(old, 0);
        int n = old_p[old_p[i]];
        utarray_push_back(new, &n);
    }

    // output
    const char* sep = "";
    for (size_t i = 0; i < utarray_len(new); i++) {
        printf("%s%d", sep, *(int*)utarray_eltptr(new, i));
        sep = " ";
    }
    printf("\n");

    utarray_free(old);
    utarray_free(new);
}