2025-12-07 18:35:22 +01:00

92 lines
2.3 KiB
C

#include "numbers.h"
#include "bintree.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
int compareUnsignedInt(const void *a, const void *b) {
unsigned int x = *(unsigned int *)a;
unsigned int y = *(unsigned int *)b;
if (x < y)
return -1;
if (x > y)
return 1;
return 0;
}
// TODO: getDuplicate und createNumbers implementieren
/**Erzeugen eines Arrays mit der vom Nutzer eingegebenen Anzahl an
* Zufallszahlen. Sicherstellen, dass beim Befüllen keine Duplikate entstehen.
* Duplizieren eines zufälligen Eintrags im Array.
* in `getDuplicate()`: Sortieren des Arrays und Erkennen der doppelten Zahl
* durch Vergleich benachbarter Elemente. */
// Returns len random numbers between 1 and 2x len in random order which are all
// different, except for two entries. Returns NULL on errors. Use your
// implementation of the binary search tree to check for possible duplicates
// while creating random numbers.
unsigned int *createNumbers(unsigned int len) {
if (len < 2)
return NULL;
unsigned int *arr = malloc(sizeof(unsigned int) * len);
if (!arr)
return NULL;
TreeNode *root = NULL;
srand((unsigned int)time(NULL));
for (unsigned int i = 0; i < len - 1; i++) {
unsigned int num;
int isDuplicate;
do {
num = (rand() % (2 * len)) + 1;
isDuplicate = 0;
root = addToTree(root, &num, sizeof(unsigned int), compareUnsignedInt,
&isDuplicate);
} while (isDuplicate); // nur akzeptieren, wenn eindeutig
arr[i] = num;
}
// Jetzt gezielt EIN Duplikat erzeugen
unsigned int duplicateIndex = rand() % (len - 1);
arr[len - 1] = arr[duplicateIndex];
clearTree(root);
return arr;
}
// Returns only the only number in numbers which is present twice. Returns zero
// on errors.
unsigned int getDuplicate(const unsigned int numbers[], unsigned int len) {
if (!numbers || len < 2)
return 0;
unsigned int *copy = malloc(sizeof(unsigned int) * len);
if (!copy)
return 0;
memcpy(copy, numbers, sizeof(unsigned int) * len);
// Sortierung
qsort(copy, len, sizeof(unsigned int), compareUnsignedInt);
// Duplikat finden: zwei gleiche nebeneinander
unsigned int duplicate = 0;
for (unsigned int i = 0; i < len - 1; i++) {
if (copy[i] == copy[i + 1]) {
duplicate = copy[i];
break;
}
}
free(copy);
return duplicate;
}