set the seed for the RNG just once at the beginning of the program

this improves randomness for tests where createNumbers() is called in rapid succession

bintree.c

@@ -1,18 +1,82 @@
 #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.
@@ -20,17 +84,72 @@ TreeNode *addToTree(TreeNode *root, const void *data, size_t dataSize, CompareFc
 // 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

@@ -39,6 +39,9 @@ int main(int argc, char *argv[])
 {
     int exitCode = EXIT_FAILURE;
 
+    // set seed
+    srand(time(NULL));
+
     if(argc != 2)
     {
         fprintf(stderr, "Usage: %s <player name>\n", argv[0]);

makefile

@@ -1,5 +1,5 @@
 CC = gcc
-FLAGS = -g -Wall -lm
+CFLAGS = -g -Wall -lm
 
 ifeq ($(OS),Windows_NT)
 	include makefile_windows.variables
@@ -27,20 +27,30 @@ doble_initial:
 program_obj_files = stack.o bintree.o numbers.o timer.o highscore.o
 
 doble : main.o $(program_obj_files)
-	$(CC) $(FLAGS) $^ -o doble
+	$(CC) $(CFLAGS) $^ -o doble
 
-$(program_obj_filesobj_files): %.o: %.c
+$(program_obj_files): %.o: %.c
-	$(CC) -c $(FLAGS) $^ -o $@
+	$(CC) -c $(CFLAGS) $^ -o $@
 
 # --------------------------
 # Unit Tests
 # --------------------------
 TEST_STACK_SOURCES = stack.c test_stack.c $(unityfolder)/unity.c
+TEST_BINTREE_SOURCES = bintree.c test_bintree.c stack.c $(unityfolder)/unity.c
+TEST_NUMBERS_SOURCES = stack.c numbers.c bintree.c $(unityfolder)/unity.c test_numbers.c
 
 stackTests: $(TEST_STACK_SOURCES) stack.h
-	$(CC) $(FLAGS) -I$(unityfolder) $(TEST_STACK_SOURCES) -o runStackTests
+	$(CC) $(CFLAGS) -I$(unityfolder) $(TEST_STACK_SOURCES) -o runStackTests
 	./runStackTests
 
+bintreeTests: $(TEST_BINTREE_SOURCES) stack.h bintree.h
+	$(CC) $(CFLAGS) -I$(unityfolder) $(TEST_BINTREE_SOURCES) -o runBintreeTests
+	./runBintreeTests
+
+numbersTests: $(TEST_NUMBERS_SOURCES) stack.h bintree.h numbers.h
+	$(CC) $(CFLAGS) -I$(unityfolder) $(TEST_NUMBERS_SOURCES) -o runNumbersTests
+	./runNumbersTests
+
 # --------------------------
 # Clean
 # --------------------------

numbers.c

@@ -5,22 +5,82 @@
 #include "numbers.h"
 #include "bintree.h"
 
-//TODO: getDuplicate und createNumbers implementieren
+static int compareInt(const void *ptr1, const void *ptr2);
+
+// TODO: getDuplicate und createNumbers implementieren
 /*  *   * Erzeugen eines Arrays mit der vom Nutzer eingegebenen Anzahl an Zufallszahlen.
-  * Sicherstellen, dass beim Befüllen keine Duplikate entstehen.
+ * Sicherstellen, dass beim Befüllen keine Duplikate entstehen.
-  * Duplizieren eines zufälligen Eintrags im Array.
+ * Duplizieren eines zufälligen Eintrags im Array.
-  * in `getDuplicate()`: Sortieren des Arrays und Erkennen der doppelten Zahl durch Vergleich benachbarter Elemente. */
+ * 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));
 
+  // including upper limit
+  int upperLimit = len * 2;
+
+  int numberCnt = 0;
+
+  int isDuplicate = 0;
+  TreeNode *root = 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
+  int dupNum = randomNumbers[rand() % numberCnt];
+  // ...and where to insert
+  int dupNumIdx = rand() % len;
+
+  // move the number currently at the dupNumIdx to the end
+  // and insert the dupNum at the index
+  // this also works if the last idx was selected for dupNum
+  randomNumbers[len - 1] = randomNumbers[dupNumIdx];
+  randomNumbers[dupNumIdx] = dupNum;
+
+  // clean up memory
+  clearTree(root);
+  return randomNumbers;
 }
 
 // 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)
 {
-
+  qsort((void *)numbers, len, sizeof(int), compareInt); // sort the array
+  for (int i = 0; i < len - 1; i++)
+  {
+    if (numbers[i] == numbers[i + 1])
+      return numbers[i];
+  }
+  return 0; // zero on errors
+}
+
+static int compareInt(const void *ptr1, const void *ptr2)
+{
+  int num1 = *(int *)ptr1;
+  int num2 = *(int *)ptr2;
+  return num1 - num2;
 }

test_bintree.c

@@ -0,0 +1,39 @@
+#include "unity.h"
+#include "bintree.h"
+#include "string.h"
+
+void setUp(void)
+{
+    // set stuff up here
+}
+
+void tearDown(void)
+{
+    // set stuff up here
+}
+
+// this adds some strings and checks if they are returned in the right order
+void test_insert_and_retrieve(void)
+{
+    char *data1 = "a_this";
+    char *data2 = "b_is";
+    char *data3 = "c_testdata";
+
+    TreeNode *root = addToTree(NULL, data1, strlen(data1) + 1, (CompareFctType)&strcmp, NULL);
+    addToTree(root, data2, strlen(data2) + 1, (CompareFctType)&strcmp, NULL);
+    addToTree(root, data3, strlen(data3) + 1, (CompareFctType)&strcmp, NULL);
+
+    TEST_ASSERT_EQUAL_STRING(data1, (char *)nextTreeData(root));
+    TEST_ASSERT_EQUAL_STRING(data2, (char *)nextTreeData(NULL));
+    TEST_ASSERT_EQUAL_STRING(data3, (char *)nextTreeData(NULL));
+
+    clearTree(root);
+}
+
+int main(void)
+{
+    printf("============================\nBintree tests\n============================\n");
+    UNITY_BEGIN();
+    RUN_TEST(test_insert_and_retrieve);
+    return UNITY_END();
+}

test_numbers.c

@@ -0,0 +1,50 @@
+#include "unity.h"
+// #include "bintree.h"
+// #include "string.h"
+#include "numbers.h"
+#include "stdlib.h"
+
+void setUp(void)
+{
+    // set stuff up here
+}
+
+void tearDown(void)
+{
+    // set stuff up here
+}
+
+// getDuplicate on array without duplicats
+// expects 0/error
+void test_get_duplicate_error(void)
+{
+    unsigned int input[] = {1, 5, 9, 2, 4};
+    unsigned int len = sizeof(input) / sizeof(input[0]);
+
+    TEST_ASSERT_EQUAL_UINT(0, getDuplicate(input, len));
+}
+
+// this tries to brute force a triple
+void test_for_triple(void)
+{
+    // this test is less effective if srand is called inside createNumbers()
+    for (int i = 0; i < 100000; i++)
+    {
+        unsigned int *numbers = createNumbers(3);
+        if (numbers[0] == numbers[1] && numbers[1] == numbers[2])
+        {
+            // fail the test
+            TEST_ASSERT(0);
+        }
+        free(numbers);
+    }
+}
+
+int main(void)
+{
+    printf("============================\nNumbers tests\n============================\n");
+    UNITY_BEGIN();
+    RUN_TEST(test_get_duplicate_error);
+    RUN_TEST(test_for_triple);
+    return UNITY_END();
+}