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

main.c

@@ -1,6 +1,5 @@
 #include <stdlib.h>
 #include <stdio.h>
-#include <time.h>
 #include "numbers.h"
 #include "timer.h"
 #include "highscore.h"
@@ -87,7 +86,6 @@ int main(int argc, char *argv[])
         saveHighscores(highscorePath);
         clearHighscores();
 
-        free(numbers);
         exitCode = EXIT_SUCCESS;
     }
 

numbers.c

@@ -26,11 +26,6 @@ unsigned int *createNumbers(unsigned int len)
 {
   unsigned int *randomNumbers = malloc(len * sizeof(int));
 
-  if (!randomNumbers)
-  {
-    return NULL;
-  }
-
   // including upper limit
   int upperLimit = len * 2;
 
@@ -74,27 +69,13 @@ unsigned int *createNumbers(unsigned int len)
 // 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)
 {
-  unsigned int *numbersCpy = malloc(sizeof(unsigned int) * len);
-  if (!numbersCpy)
-  {
-    return 0;
-  }
-  memcpy(numbersCpy, numbers, len * sizeof(unsigned int));
-  numbersCpy = numbersCpy; // shadow the numbers array with copy
-
-  qsort((void *)numbersCpy, len, sizeof(int), compareInt); // sort the array
-
-  unsigned int duplicateFound = 0; // zero on errors
+  qsort((void *)numbers, len, sizeof(int), compareInt); // sort the array
   for (int i = 0; i < len - 1; i++)
   {
-    if (numbersCpy[i] == numbersCpy[i + 1])
-    {
-      duplicateFound = numbersCpy[i];
-      break;
-    }
+    if (numbers[i] == numbers[i + 1])
+      return numbers[i];
   }
-  free(numbersCpy);
-  return duplicateFound;
+  return 0; // zero on errors
 }
 
 static int compareInt(const void *ptr1, const void *ptr2)

test_numbers.c

@@ -1,9 +1,8 @@
 #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)
 {
@@ -17,7 +16,7 @@ void tearDown(void)
 
 // getDuplicate on array without duplicats
 // expects 0/error
-void test_get_duplicate_without_duplicates(void)
+void test_get_duplicate_error(void)
 {
     unsigned int input[] = {1, 5, 9, 2, 4};
     unsigned int len = sizeof(input) / sizeof(input[0]);
@@ -25,21 +24,6 @@ void test_get_duplicate_without_duplicates(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)
 {
@@ -49,79 +33,18 @@ void test_for_triple(void)
         unsigned int *numbers = createNumbers(3);
         if (numbers[0] == numbers[1] && numbers[1] == numbers[2])
         {
-            TEST_FAIL_MESSAGE("triple generated");
+            // fail the test
+            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_without_duplicates);
+    RUN_TEST(test_get_duplicate_error);
     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();
 }

timer.c

@@ -1,12 +1,6 @@
 #include "timer.h"
 
-#ifdef __linux__
-// Defines strict posix compliance for CLOCK_MONOTONIC
-#define _POSIX_C_SOURCE 199309L
-#include <time.h>
-#endif
-
-#if __APPLE__ || __linux__
+#if __APPLE__
 #include <sys/time.h>
 static struct timespec start = {0, 0};
 
@@ -20,15 +14,14 @@ void startTimer()
 double stopTimer()
 {
     struct timespec end;
-
+    
     clock_gettime(CLOCK_MONOTONIC, &end);
 
     unsigned long long delta_us = (end.tv_sec - start.tv_sec) * 1000000 + (end.tv_nsec - start.tv_nsec) / 1000;
 
     double measuredSeconds = (double)delta_us / 1000000.;
 
-    if (start.tv_nsec > 0)
-    {
+    if(start.tv_nsec > 0) {
         start.tv_nsec = 0;
         start.tv_sec = 0;
     }
@@ -52,7 +45,7 @@ double stopTimer()
 {
     double measuredSeconds = (clock() - (double)startClocks) / CLOCKS_PER_SEC;
 
-    if (startClocks > 0)
+    if(startClocks > 0)
         startClocks = 0;
     else
         measuredSeconds = -1;