From 00717dd038b2c024b529553b5c2a848fceccf2fb Mon Sep 17 00:00:00 2001
From: bronku <bronk.jakub@proton.me>
Date: Thu, 23 Oct 2025 17:23:58 +0200
Subject: [PATCH] heap

---
 heap.c      | 101 ++++++++++++------
 heap.h      |  19 ++--
 heap_test.c | 302 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 makefile    |  11 +-
 4 files changed, 387 insertions(+), 46 deletions(-)
 create mode 100644 heap_test.c

diff --git a/heap.c b/heap.c
index 7ba34bb..2d9825f 100644
--- a/heap.c
+++ b/heap.c
@@ -1,45 +1,78 @@
 #include "heap.h"
 #include "status_codes.h"
+#include <stdlib.h>
 
-// #unteasted
-int heap_push(heap* h, heap_record* in)
+heap* create_heap(int size, int (*comparison)(const void* a, const void* b))
 {
-    if (h->length >= h->capacity) {
-        return NO_SPACE;
-    }
+    heap* out = malloc(sizeof(heap));
+    out->data = malloc(sizeof(void*) * size);
+    out->length = 0;
+    out->capacity = size;
+    out->compare = comparison;
+    return out;
+}
 
-    int current_index = h->length;
+void destroy_heap(heap* h)
+{
+    free(h->data);
+    free(h);
+}
+
+void swap(void** a, void** b)
+{
+    void* tmp = *a;
+    *a = *b;
+    *b = tmp;
+}
+
+int heap_push(heap* h, void* in)
+{
+    int current = h->length;
+    void** d = h->data;
     h->length++;
-    heap_record* last = h->location;
-    last += current_index;
-    *last = *in;
-
-    if (current_index == 0) {
+    d[current] = in;
+    if (current == 0) {
         return SUCCESS;
     }
-
-    int parent_index = (current_index - 1) / 2;
-    // check if violated heap property
-    heap_record* parent = h->location;
-    parent += parent_index;
-    heap_record* current = h->location;
-    current += current_index;
-    // swim up
-    while (current_index != 0 && h->compare(parent, current) == 1) {
-        // current, parent = parent, current
-        heap_record tmp = *current;
-        *current = *parent;
-        *parent = tmp;
-        // current_index = parent_index
-        current_index = parent_index;
-        // parent_index = (current_index -1 )/2
-        parent_index = (current_index - 1) / 2;
-        // current = loc[current_index]
-        current = h->location;
-        current += current_index;
-        // parent = loc[parent_index]
-        parent = h->location;
-        parent_index += parent_index;
+    int parent = (current - 1) / 2;
+    while (h->compare(d[current], d[parent]) == -1) {
+        swap(&d[current], &d[parent]);
+        current = parent;
+        if (current == 0) {
+            break;
+        }
+        parent = (current - 1) / 2;
+    }
+    return SUCCESS;
+}
+
+int heap_pop(heap* h, void** out)
+{
+    void** d = h->data;
+    *out = d[0];
+    h->length--;
+    if (h->length == 0) {
+        return SUCCESS;
+    }
+    swap(&d[0], &d[h->length]);
+    int current = 0;
+    int left = current * 2 + 1;
+    int right = current * 2 + 2;
+    while (true) {
+        int smallest = current;
+        if (left < h->length && h->compare(d[smallest], d[left]) == 1) {
+            smallest = left;
+        }
+        if (right < h->length && h->compare(d[smallest], d[right]) == 1) {
+            smallest = right;
+        }
+        if (smallest == current) {
+            break;
+        }
+        swap(&d[smallest], &d[current]);
+        current = smallest;
+        left = current * 2 + 1;
+        right = current * 2 + 2;
     }
     return SUCCESS;
 }
diff --git a/heap.h b/heap.h
index f59116d..601745b 100644
--- a/heap.h
+++ b/heap.h
@@ -1,22 +1,19 @@
+// doesn't ceck for user erros, so no veryfying that the void* supplied are valid
+// unsafe for general use, but just fnuctional enough for the purposes of this project
+// does not maintain ownership of its elements, they are managed by the caller
 #pragma once
 
 #include "stdbool.h"
 
 typedef struct {
-    int index;
-    int buffer_id;
-} heap_record;
-
-// almost the same as typedef buffer, but the usage is different, so I think it can be repeated
-typedef struct {
-    heap_record* location;
+    void** data;
     int length;
     int capacity;
     int (*compare)(const void* a, const void* b);
 } heap;
 
-heap new_heap(int size);
-// free_heap is just free(h->location), so it's kinda unnecessary
+heap* create_heap(int size, int (*comparison)(const void* a, const void* b));
+void destroy_heap(heap* h);
 
-int heap_pop(heap* h, heap_record* out);
-int heap_push(heap* h, heap_record* in);
+int heap_pop(heap* h, void** out);
+int heap_push(heap* h, void* in);
diff --git a/heap_test.c b/heap_test.c
new file mode 100644
index 0000000..8462e59
--- /dev/null
+++ b/heap_test.c
@@ -0,0 +1,302 @@
+// the tests are ai generated
+#include "heap.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+// Comparator for integers
+int compare_ints(const void* a, const void* b)
+{
+    int ia = *(const int*)a;
+    int ib = *(const int*)b;
+    return (ia > ib) - (ia < ib);
+}
+
+// Comparator for doubles
+int compare_doubles(const void* a, const void* b)
+{
+    double da = *(const double*)a;
+    double db = *(const double*)b;
+    if (da < db)
+        return -1;
+    if (da > db)
+        return 1;
+    return 0;
+}
+
+// Test structure
+typedef struct {
+    int priority;
+    char name[32];
+} Task;
+
+// Comparator for tasks (by priority)
+int compare_tasks(const void* a, const void* b)
+{
+    const Task* ta = (const Task*)a;
+    const Task* tb = (const Task*)b;
+    return (ta->priority > tb->priority) - (ta->priority < tb->priority);
+}
+
+void test_basic_push_pop()
+{
+    printf("Test: Basic push and pop... ");
+
+    heap* h = create_heap(5, compare_ints);
+    int values[] = { 5, 3, 7, 1, 9 };
+
+    // Push all values
+    for (int i = 0; i < 5; i++) {
+        heap_push(h, &values[i]);
+    }
+
+    // Pop and verify they come out in sorted order
+    void* out;
+    int expected[] = { 1, 3, 5, 7, 9 };
+    for (int i = 0; i < 5; i++) {
+        heap_pop(h, &out);
+        assert(*(int*)out == expected[i]);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_single_element()
+{
+    printf("Test: Single element... ");
+
+    heap* h = create_heap(1, compare_ints);
+    int val = 42;
+
+    heap_push(h, &val);
+
+    void* out;
+    heap_pop(h, &out);
+    assert(*(int*)out == 42);
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_already_sorted()
+{
+    printf("Test: Already sorted input... ");
+
+    heap* h = create_heap(5, compare_ints);
+    int values[] = { 1, 2, 3, 4, 5 };
+
+    for (int i = 0; i < 5; i++) {
+        heap_push(h, &values[i]);
+    }
+
+    void* out;
+    for (int i = 0; i < 5; i++) {
+        heap_pop(h, &out);
+        assert(*(int*)out == i + 1);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_reverse_sorted()
+{
+    printf("Test: Reverse sorted input... ");
+
+    heap* h = create_heap(5, compare_ints);
+    int values[] = { 5, 4, 3, 2, 1 };
+
+    for (int i = 0; i < 5; i++) {
+        heap_push(h, &values[i]);
+    }
+
+    void* out;
+    for (int i = 0; i < 5; i++) {
+        heap_pop(h, &out);
+        assert(*(int*)out == i + 1);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_duplicates()
+{
+    printf("Test: Duplicate values... ");
+
+    heap* h = create_heap(7, compare_ints);
+    int values[] = { 3, 1, 4, 1, 5, 9, 2 };
+
+    for (int i = 0; i < 7; i++) {
+        heap_push(h, &values[i]);
+    }
+
+    void* out;
+    int expected[] = { 1, 1, 2, 3, 4, 5, 9 };
+    for (int i = 0; i < 7; i++) {
+        heap_pop(h, &out);
+        assert(*(int*)out == expected[i]);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_with_doubles()
+{
+    printf("Test: Double precision values... ");
+
+    heap* h = create_heap(5, compare_doubles);
+    double values[] = { 3.14, 1.41, 2.71, 0.57, 1.61 };
+
+    for (int i = 0; i < 5; i++) {
+        heap_push(h, &values[i]);
+    }
+
+    void* out;
+    double expected[] = { 0.57, 1.41, 1.61, 2.71, 3.14 };
+    for (int i = 0; i < 5; i++) {
+        heap_pop(h, &out);
+        assert(*(double*)out == expected[i]);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_with_structs()
+{
+    printf("Test: Custom struct (tasks by priority)... ");
+
+    heap* h = create_heap(4, compare_tasks);
+    Task tasks[] = {
+        { 3, "Low priority" },
+        { 1, "High priority" },
+        { 2, "Medium priority" },
+        { 1, "Also high priority" }
+    };
+
+    for (int i = 0; i < 4; i++) {
+        heap_push(h, &tasks[i]);
+    }
+
+    void* out;
+    int expected_priorities[] = { 1, 1, 2, 3 };
+    for (int i = 0; i < 4; i++) {
+        heap_pop(h, &out);
+        Task* t = (Task*)out;
+        assert(t->priority == expected_priorities[i]);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_interleaved_operations()
+{
+    printf("Test: Interleaved push/pop... ");
+
+    heap* h = create_heap(10, compare_ints);
+    int values[] = { 5, 3, 7, 1, 9, 2, 8, 4, 6, 0 };
+
+    // Push 5, pop 1, push 3 more, pop 2, etc.
+    heap_push(h, &values[0]); // 5
+    heap_push(h, &values[1]); // 3
+    heap_push(h, &values[2]); // 7
+
+    void* out;
+    heap_pop(h, &out);
+    assert(*(int*)out == 3);
+
+    heap_push(h, &values[3]); // 1
+    heap_push(h, &values[4]); // 9
+    heap_push(h, &values[5]); // 2
+
+    heap_pop(h, &out);
+    assert(*(int*)out == 1);
+    heap_pop(h, &out);
+    assert(*(int*)out == 2);
+
+    heap_push(h, &values[6]); // 8
+    heap_push(h, &values[7]); // 4
+
+    heap_pop(h, &out);
+    assert(*(int*)out == 4);
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_large_heap()
+{
+    printf("Test: Large heap (1000 elements)... ");
+
+    heap* h = create_heap(1000, compare_ints);
+    int* values = malloc(1000 * sizeof(int));
+
+    // Insert values in random-ish order
+    for (int i = 0; i < 1000; i++) {
+        values[i] = (i * 7 + 13) % 1000;
+        heap_push(h, &values[i]);
+    }
+
+    // Pop all and verify sorted
+    void* out;
+    int prev = -1;
+    for (int i = 0; i < 1000; i++) {
+        heap_pop(h, &out);
+        int curr = *(int*)out;
+        assert(curr >= prev);
+        prev = curr;
+    }
+
+    free(values);
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+void test_all_same_values()
+{
+    printf("Test: All same values... ");
+
+    heap* h = create_heap(5, compare_ints);
+    int val = 42;
+    int values[5];
+
+    for (int i = 0; i < 5; i++) {
+        values[i] = val;
+        heap_push(h, &values[i]);
+    }
+
+    void* out;
+    for (int i = 0; i < 5; i++) {
+        heap_pop(h, &out);
+        assert(*(int*)out == 42);
+    }
+
+    destroy_heap(h);
+    printf("PASSED\n");
+}
+
+int main()
+{
+    printf("Running Min Heap Tests\n");
+    printf("======================\n\n");
+
+    test_basic_push_pop();
+    test_single_element();
+    test_already_sorted();
+    test_reverse_sorted();
+    test_duplicates();
+    test_with_doubles();
+    test_with_structs();
+    test_interleaved_operations();
+    test_large_heap();
+    test_all_same_values();
+
+    printf("\n======================\n");
+    printf("All tests PASSED! ✓\n");
+
+    return 0;
+}
diff --git a/makefile b/makefile
index f72b723..6dd82d5 100644
--- a/makefile
+++ b/makefile
@@ -33,7 +33,16 @@ build/run/1.in: build/run build/main
 run: build/main build/run/1.in build/run/tmp
 	build/main -i build/run/1.in -d build/run/tmp | less
 
+build/heap_test.o: heap_test.c build
+	clang $(CFLAGS) -c heap_test.c -o build/heap_test.o
+
+build/test: build/heap_test.o build/heap.o
+	clang $(CFLAGS) build/heap_test.o build/heap.o -o build/test
+
+test: build/test
+	build/test
+
 debug: build/main tests/1.in
 	lldb -- build/main
 
-.PHONY: clean run debug
+.PHONY: clean run debug test