remove vla

Reviewed-on: #1

bintree.c

@@ -1,82 +1,18 @@
 #include <string.h>
 #include "stack.h"
 #include "bintree.h"
-#include <stdlib.h>
 
-// TODO: binären Suchbaum implementieren
+//TODO: binären Suchbaum implementieren
 /*  * `addToTree`: fügt ein neues Element in den Baum ein (rekursiv),
- * `clearTree`: gibt den gesamten Baum frei (rekursiv),
+    * `clearTree`: gibt den gesamten Baum frei (rekursiv),
- * `treeSize`: zählt die Knoten im Baum (rekursiv),
+    * `treeSize`: zählt die Knoten im Baum (rekursiv),
- * `nextTreeData`: Traversierung mit Hilfe des zuvor implementierten Stacks. */
+    * `nextTreeData`: Traversierung mit Hilfe des zuvor implementierten Stacks. */
 
 // Adds a copy of data's pointer destination to the tree using compareFct for ordering. Accepts duplicates
 // if isDuplicate is NULL, otherwise ignores duplicates and sets isDuplicate to 1 (or to 0 if a new entry is added).
 TreeNode *addToTree(TreeNode *root, const void *data, size_t dataSize, CompareFctType compareFct, int *isDuplicate)
 {
-    TreeNode *insertedNode;
 
-    // create a new node if the current node is NULL
-    if (root == NULL)
-    {
-        // it's important to zero the pointers for adjacent nodes
-        insertedNode = calloc(1, sizeof(TreeNode));
-        if (!insertedNode)
-        {
-            return NULL;
-        }
-
-        insertedNode->data = malloc(dataSize);
-        if (!insertedNode->data)
-        {
-            return NULL;
-        }
-        memcpy(insertedNode->data, data, dataSize);
-        // reset isDuplicate if it exists
-        if (isDuplicate)
-        {
-            *isDuplicate = 0;
-        }
-        return insertedNode;
-    }
-
-    // TODO: what is the correct data type here?
-    int cmpRes = (*compareFct)(data, root->data);
-    // insert into the left branch
-    if (cmpRes < 0 || (cmpRes == 0 && isDuplicate == NULL))
-    {
-        root->left = addToTree(root->left, data, dataSize, compareFct, isDuplicate);
-    }
-    // insert into the right branch
-    else if (cmpRes > 0)
-    {
-        root->right = addToTree(root->right, data, dataSize, compareFct, isDuplicate);
-    }
-    // the data is equal to the current node
-    else
-    {
-        // the data already exists in the tree and duplicates are ignored (isDuplicate* not NULL)
-        *isDuplicate = 1;
-    }
-    return root;
-}
-
-// push all left descendants from @param node
-static void pushLeftDesc(StackNode **stackPtr, TreeNode *node)
-{
-    if (!stackPtr || !node)
-    {
-        return;
-    }
-    TreeNode *curNode = node;
-    while (curNode->left)
-    {
-        *stackPtr = push(*stackPtr, curNode->left);
-        if (!*stackPtr)
-        {
-            return;
-        }
-        curNode = curNode->left;
-    }
 }
 
 // Iterates over the tree given by root. Follows the usage of strtok. If tree is NULL, the next entry of the last tree given is returned in ordering direction.
@@ -84,72 +20,17 @@ static void pushLeftDesc(StackNode **stackPtr, TreeNode *node)
 // push the top node and push all its left nodes.
 void *nextTreeData(TreeNode *root)
 {
-    // this creates a static variable that maintains an internal state
-    static StackNode *stack;
 
-    // create a new stack
-    if (root)
-    {
-        // clear possibly existing stacks
-        clearStack(stack);
-        // init a new stack
-        stack = push(NULL, root);
-        // init failed
-        if (!stack)
-        {
-            return NULL;
-        }
-        pushLeftDesc(&stack, root);
-
-        // return the first val
-        return nextTreeData(NULL);
-    }
-
-    // neither stack nor root exist
-    if (!stack)
-    {
-        return NULL;
-    }
-
-    // get next val with stack
-    TreeNode *res = top(stack);
-    stack = pop(stack);
-    if (res->right)
-    {
-        stack = push(stack, res->right);
-        pushLeftDesc(&stack, res->right);
-    }
-
-    return res->data;
 }
 
 // Releases all memory resources (including data copies).
 void clearTree(TreeNode *root)
 {
-    // this check is crucial for recursion
-    if (!root)
-    {
-        // nothing to clear
-        return;
-    }
 
-    // release the resources of child nodes first
-    clearTree(root->left);
-    clearTree(root->right);
-
-    // free the data (it's just a copy created in addToTree())
-    free(root->data);
-    free(root);
 }
 
 // Returns the number of entries in the tree given by root.
 unsigned int treeSize(const TreeNode *root)
 {
-    // there are no nodes
-    if (!root)
-    {
-        return 0;
-    }
 
-    return 1 + treeSize(root->left) + treeSize(root->right);
 }

main.c

@@ -71,7 +71,7 @@ int main(int argc, char *argv[])
         userInput = inputNumber("Welche Zahl kommt doppelt vor: ");
         measuredSeconds = stopTimer();
 
-        duplicate = getDuplicate(numbers, numberOfElements);
+        duplicate = getDuplicate(numbers, numberOfElements+1);
 
         // check result and update highscores
         if(userInput == duplicate)

numbers.c

@@ -5,87 +5,61 @@
 #include "numbers.h"
 #include "bintree.h"
 
-static int compareInt(const void *ptr1, const void *ptr2);
+//Speicher für Array erstellen, zufällige Zahlen von 1-2xlen erzeugen, mittels Binärbaum checken, ob Zahlen einzigartig sind
+//Eine Zahl duplizieren, an zufälliger Stelle einfügen und die Zahl an der Stelle ans Ende schieben
+const int compare (const void *a, const void *b);
 
-// 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.
-
-/*
-the implemented tree can't efficiently check if it contains a specific number, but we don't actually need that anyways
-create numbers just counts and checks if the just inserted number sets the isDuplicate pointer
-*/
-// srand should have been called before this function
 unsigned int *createNumbers(unsigned int len)
 {
-  unsigned int *randomNumbers = malloc(len * sizeof(int));
+  unsigned int *numbers = malloc (sizeof(unsigned int) * len);
-
+  unsigned int upperLimit = len * 2;
-  if (!randomNumbers)
-  {
-    return NULL;
-  }
-
-  // including upper limit
-  int upperLimit = len * 2;
-
-  int numberCnt = 0;
-
   int isDuplicate = 0;
-  TreeNode *root = NULL;
+  TreeNode *binTree = NULL;
-  // we only need len-1 numbers because 1 will be duplicated
-  while (numberCnt < len - 1)
-  {
-    // numbers up to and including upperLimit without 0
-    int randNum = rand() % upperLimit + 1;
-    // reset isDuplicate
-    isDuplicate = 0;
-    // don't forget to set the root here
-    root = addToTree(root, &randNum, sizeof(randNum), (CompareFctType)compareInt, &isDuplicate);
-    if (isDuplicate)
-    {
-      // number already exists
-      continue;
-    }
-    randomNumbers[numberCnt++] = randNum;
-  }
 
-  // select which number to duplicate
+  for (unsigned int i = 0; i < len; i++) {
-  int dupNum = randomNumbers[rand() % numberCnt];
+    do
-  // ...and where to insert
+    { 
-  int dupNumIdx = rand() % len;
+      numbers[i] = rand () % upperLimit + 1;
+      binTree = addToTree(binTree, &numbers[i], sizeof(unsigned int), compare, &isDuplicate);
+    } while (isDuplicate);
+  } 
 
-  // move the number currently at the dupNumIdx to the end
+  unsigned int duplicate = numbers[rand () % len];
-  // and insert the dupNum at the index
+  int indexDuplicate = rand () % len;
-  // this also works if the last idx was selected for dupNum
+  numbers[len] = numbers[indexDuplicate];
-  randomNumbers[len - 1] = randomNumbers[dupNumIdx];
+  numbers[indexDuplicate] = duplicate;
-  randomNumbers[dupNumIdx] = dupNum;
 
-  // clean up memory
+  return numbers;
-  clearTree(root);
-  return randomNumbers;
 }
 
-// Returns only the only number in numbers which is present twice. Returns zero on errors.
+//Vergleichsfunktion von qsort
+const int compare (const void *a, const void *b) {
+  const unsigned int *x = a;
+  const unsigned int *y = b;
+  if (*x < *y) {
+    return -1;
+  }
+  else if (*x > *y) {
+    return 1;
+  }
+  else {
+    return 0;
+  }
+}
+
+//Sortiert Zahlen mit qsort, vergleicht dann benachbarte Elemente und gibt bei Erfolg die doppelte Zahl zurück
 unsigned int getDuplicate(const unsigned int numbers[], unsigned int len)
 {
-  qsort((void *)numbers, len, sizeof(int), compareInt); // sort the array
+  if (len < 2) {
-  for (int i = 0; i < len - 1; i++)
+    return 0;
-  {
-    if (numbers[i] == numbers[i + 1])
-      return numbers[i];
   }
-  return 0; // zero on errors
-}
 
-static int compareInt(const void *ptr1, const void *ptr2)
+qsort((void*)numbers, len, sizeof(unsigned int), compare);
-{
+
-  int num1 = *(int *)ptr1;
+for (int i = 0; i < len-1; i++) {
-  int num2 = *(int *)ptr2;
+  if (numbers[i] == numbers [i+1]) {
-  return num1 - num2;
+    return numbers[i];
+  }
+}
+  return 0;
 }

test_numbers.c

@@ -1,8 +1,9 @@
 #include "unity.h"
-// #include "bintree.h"
-// #include "string.h"
 #include "numbers.h"
 #include "stdlib.h"
+#include "string.h"
+
+static int compareInt(const void *ptr1, const void *ptr2);
 
 void setUp(void)
 {
@@ -16,7 +17,7 @@ void tearDown(void)
 
 // getDuplicate on array without duplicats
 // expects 0/error
-void test_get_duplicate_error(void)
+void test_get_duplicate_without_duplicates(void)
 {
     unsigned int input[] = {1, 5, 9, 2, 4};
     unsigned int len = sizeof(input) / sizeof(input[0]);
@@ -24,6 +25,21 @@ void test_get_duplicate_error(void)
     TEST_ASSERT_EQUAL_UINT(0, getDuplicate(input, len));
 }
 
+// getDuplicate() on some arrays with 1 duplicate
+void test_get_duplicate(void)
+{
+    unsigned int arr1[] = {4, 15, 32, 5, 3, 8, 8};
+    unsigned int len1 = sizeof(arr1) / sizeof(arr1[0]);
+    unsigned int arr2[] = {1, 3, 3, 7};
+    unsigned int len2 = sizeof(arr2) / sizeof(arr2[0]);
+    unsigned int arr3[] = {7, 7, 8, 4, 9, 1};
+    unsigned int len3 = sizeof(arr3) / sizeof(arr3[0]);
+
+    TEST_ASSERT_EQUAL_UINT(8, getDuplicate(arr1, len1));
+    TEST_ASSERT_EQUAL_UINT(3, getDuplicate(arr2, len2));
+    TEST_ASSERT_EQUAL_UINT(7, getDuplicate(arr3, len3));
+}
+
 // this tries to brute force a triple
 void test_for_triple(void)
 {
@@ -33,18 +49,79 @@ void test_for_triple(void)
         unsigned int *numbers = createNumbers(3);
         if (numbers[0] == numbers[1] && numbers[1] == numbers[2])
         {
-            // fail the test
+            TEST_FAIL_MESSAGE("triple generated");
-            TEST_ASSERT(0);
         }
         free(numbers);
     }
 }
 
+// check if getDuplicate() modifies the original array (it should not)
+void test_get_duplicate_does_modify()
+{
+    unsigned int arr1[] = {1, 2, 3, 4, 5, 4, 3, 2, 1}; // sorting would change this
+    size_t len1 = sizeof(arr1) / sizeof(arr1[0]);
+    unsigned int arr1Copy[9];
+    memcpy(arr1Copy, arr1, len1 * sizeof(unsigned int));
+
+    getDuplicate(arr1, len1); // return value does not matter
+
+    // check if the arrays are still the same
+    if (memcmp(arr1, arr1Copy, len1 * sizeof(unsigned int)))
+    {
+        TEST_FAIL_MESSAGE("Arrays have diverged");
+    }
+}
+
+// checks if there is exactly 1 duplicate number at varying array sizes
+void test_exactly_one_duplicate()
+{
+    const size_t MAX_LIST_SIZE = 20;      // max tested array len
+    const size_t ITERATIONS_PER_LEN = 20; // number of iterations for each tested array len
+
+    for (size_t len = 2; len < MAX_LIST_SIZE; len++) // start with smallest sensible size 2
+    {
+        for (size_t i = 0; i < ITERATIONS_PER_LEN; i++)
+        {
+            unsigned int *randTestList = createNumbers((unsigned int)len);
+
+            qsort(randTestList, len, sizeof(unsigned int), compareInt);
+
+            int cntDuplicate = 0;
+            for (size_t j = 0; j < len - 1; j++)
+            {
+                if (randTestList[j] == randTestList[j + 1])
+                {
+                    cntDuplicate++;
+                }
+            }
+            // there should be exactly 1 duplicate
+            TEST_ASSERT_EQUAL_INT(1, cntDuplicate);
+
+            free(randTestList);
+        }
+    }
+}
+
+static int compareInt(const void *ptr1, const void *ptr2)
+{
+    unsigned int num1 = *(int *)ptr1;
+    unsigned int num2 = *(int *)ptr2;
+
+    if (num1 < num2)
+        return -1;
+    if (num1 > num2)
+        return 1;
+    return 0;
+}
+
 int main(void)
 {
     printf("============================\nNumbers tests\n============================\n");
     UNITY_BEGIN();
-    RUN_TEST(test_get_duplicate_error);
+    RUN_TEST(test_get_duplicate_without_duplicates);
     RUN_TEST(test_for_triple);
+    RUN_TEST(test_exactly_one_duplicate);
+    RUN_TEST(test_get_duplicate);
+    RUN_TEST(test_get_duplicate_does_modify);
     return UNITY_END();
 }