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

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
int *
findIndices(int* nums, int numsSize, int indexDifference, int valueDifference, int* returnSize)
{
    int *ret = malloc(2*sizeof(int));
    ret[0] = -1;
    ret[1] = -1;

    for ( int i = 0; i < numsSize; ++i ) {
        for ( int j = i; j < numsSize; ++j ) {
            if ( abs(i-j) < indexDifference ) { continue; }
            if ( abs(nums[i]-nums[j]) < valueDifference ) { continue; }
            ret[0] = i;
            ret[1] = j;
            goto exit;
        }
    }

exit:
    *returnSize = 2;
    return ret;
}

char *
list_to_cstr_temp(int *nums, int numsSize)
{
    char *data = NULL;
    unsigned long size = 0;
    unsigned long cap = 1024;

    size = 0;
    if ( data == NULL ) { data = malloc(cap * sizeof(*data)); }
    memset(data, 0, cap);

    data[size++] = '[';
    for ( int i = 0; i < numsSize; ++i ) {
        if ( size + 2 >= cap ) { cap *= 2; data = realloc(data, cap); }
        if ( i > 0 ) { data[size++] = ','; }
        data[size++] = nums[i] + '0';
    }
    data[size++] = ']';
    data[size++] = '\0';

    return data;
}

void
r(int *nums, int numsSize, int indexDifference, int valueDifference, int *exp)
{
    int t;
    char *numsCstr = list_to_cstr_temp(nums, numsSize);
    int *ret = findIndices(nums, numsSize, indexDifference, valueDifference, &t);
    char *retCstr = list_to_cstr_temp(ret, 2);
    char *expCstr = list_to_cstr_temp(exp, 2);
    printf("findIndices(%s, %d, %d, %d) = %s | exp: %s\n",
           numsCstr, numsSize, indexDifference, valueDifference,
           retCstr,
           expCstr);

    free(numsCstr);
    free(ret);
    free(retCstr);
    free(expCstr);
}

int
main(void)
{
    int nums1[] = {5,1,4,1};
    int exp1[] = {0,3};
    r(nums1, 4, 2, 4, exp1);

    int nums2[] = {2,1};
    int exp2[] = {0,0};
    r(nums2, 2, 0, 0, exp2);

    int nums3[] = {1,2,3};
    int exp3[] = {-1,-1};
    r(nums3, 3, 2, 4, exp3);

    return 0;
}