From bf8d8f5139983bd4480fbb21b907d0278830bdc2 Mon Sep 17 00:00:00 2001
From: Simon Wiesend <wiesendsi102436@th-nuernberg.de>
Date: Sun, 7 Dec 2025 17:09:53 +0100
Subject: [PATCH] add some numbers.c tests

---
 test_numbers.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 63 insertions(+), 4 deletions(-)

diff --git a/test_numbers.c b/test_numbers.c
index a7e6872..630d239 100644
--- a/test_numbers.c
+++ b/test_numbers.c
@@ -1,9 +1,9 @@
 #include "unity.h"
-// #include "bintree.h"
-// #include "string.h"
 #include "numbers.h"
 #include "stdlib.h"
 
+static int compareInt(const void *ptr1, const void *ptr2);
+
 void setUp(void)
 {
     // set stuff up here
@@ -16,7 +16,7 @@ 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 +24,21 @@ 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, 8, 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)
 {
@@ -40,11 +55,55 @@ void test_for_triple(void)
     }
 }
 
+// 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);
     return UNITY_END();
 }
\ No newline at end of file