91 lines
2.5 KiB
C
91 lines
2.5 KiB
C
#include <stdlib.h>
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#include <stdio.h>
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#include <time.h>
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#include <string.h>
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#include "numbers.h"
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#include "bintree.h"
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//TODO: getDuplicate und createNumbers implementieren
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/* * * Erzeugen eines Arrays mit der vom Nutzer eingegebenen Anzahl an Zufallszahlen.
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* Sicherstellen, dass beim Befüllen keine Duplikate entstehen.
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* Duplizieren eines zufälligen Eintrags im Array.
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* in `getDuplicate()`: Sortieren des Arrays und Erkennen der doppelten Zahl durch Vergleich benachbarter Elemente. */
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// Returns len random numbers between 1 and 2x len in random order which are all different, except for two entries.
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// Returns NULL on errors. Use your implementation of the binary search tree to check for possible duplicates while
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// creating random numbers.
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unsigned int *createNumbers(unsigned int len)
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{
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if (len < 2) return NULL;
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unsigned int *numbers = malloc(len * sizeof(unsigned int));
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if (!numbers) return NULL;
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srand((unsigned int)time(NULL));
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TreeNode *root = NULL;
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unsigned int maxValue = 2 * len;
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unsigned int uniqueCount = len - 1; // we generate len-1 unique values
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unsigned int i = 0;
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// Fill len - 1 unique values using BST
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while (i < uniqueCount) {
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unsigned int r = (rand() % maxValue) + 1;
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int isDup = 0;
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root = addToTree(root, &r, sizeof(unsigned int), compareUnsigned, &isDup);
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if (!isDup) {
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numbers[i] = r;
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i++;
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}
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}
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// Pick one number already in the list → duplicate it
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unsigned int duplicateIndex = rand() % uniqueCount;
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unsigned int duplicateValue = numbers[duplicateIndex];
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numbers[len - 1] = duplicateValue;
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// Cleanup tree
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clearTree(root);
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// Shuffle array for randomness
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for (unsigned int j = 0; j < len; j++) {
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unsigned int k = rand() % len;
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unsigned int tmp = numbers[j];
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numbers[j] = numbers[k];
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numbers[k] = tmp;
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}
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return numbers;
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}
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// Returns only the only number in numbers which is present twice. Returns zero on errors.
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unsigned int getDuplicate(const unsigned int numbers[], unsigned int len)
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{
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if (!numbers || len < 2) return 0;
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// Make a copy because qsort modifies the array
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unsigned int *copy = malloc(len * sizeof(unsigned int));
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if (!copy) return 0;
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memcpy(copy, numbers, len * sizeof(unsigned int));
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qsort(copy, len, sizeof(unsigned int), compareUnsigned);
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// Check adjacent elements for equality
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for (unsigned int i = 0; i < len - 1; i++) {
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if (copy[i] == copy[i + 1]) {
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unsigned int result = copy[i];
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free(copy);
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return result;
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}
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}
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free(copy);
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return 0; // no duplicate found (should not happen)
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}
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