Should work

mem_man.c

@@ -28,68 +28,166 @@
  * shall be maintained in a linked list.
  */
 
-#define MEMORY_BLOCK_CNT 1024;
+#define MEMORY_BLOCK_CNT 1024
+#define BYTES_PER_BLOCK 4
 
+static int memory[MEMORY_BLOCK_CNT];
+static size_t allocatedBlocks = 0;
+static size_t freeBlocks = MEMORY_BLOCK_CNT;
+
+static void init_memory() {
+    static int initialized = 0;
+    if (!initialized) {
+        for (size_t i = 0; i < MEMORY_BLOCK_CNT; i++) {
+            memory[i] = 0xAFFEBAFF;
+        }
+        initialized = 1;
+    }
+}
 
-/**
- * Allocates a memory block of the given size in bytes
- * in a similar way as `malloc(size)`.
- * 
- * @param size The number of bytes to allocate.
- * @return The pointer to the allocated memory block or 0,
- * if no memory could be allocated.
- */
 void *my_alloc(size_t size) {
-    return 0;
+    init_memory();
+    
+    if (size == 0) {
+        return (void*)0;
+    }
+    
+    size_t i = 0;
+    size_t start = MEMORY_BLOCK_CNT;
+    size_t freePlaces = 0;
+    size_t blocks_needed = (size + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;
+
+    while (i < MEMORY_BLOCK_CNT) {
+        if (memory[i] == 0xAFFEBAFF) {
+            if (freePlaces == 0) {
+                start = i;
+            }
+            freePlaces++;
+
+            if (freePlaces == blocks_needed) {
+                for (size_t j = 0; j < blocks_needed; j++) {
+                    memory[start + j] = 0xDEADBEEF;
+                }
+                freeBlocks -= blocks_needed;
+                allocatedBlocks += blocks_needed;
+                return &memory[start];
+            }
+        } else {
+            freePlaces = 0;
+            start = MEMORY_BLOCK_CNT;
+        }
+        i++;
+    }
+    return NULL;
 }
 
-/**
- * Releases the addressed memory block that was allocated via function `my_alloc(...)`.
- * If the addressed memory is not allocated, a warning is printed.
- * 
- * @param p The pointer to the memory to free.
- */
 void my_free(void *p) {
+    int start = get_unit_index(p);
+    if (start == -1) {
+        printf("Memory is not allocated\n");
         return;
     }
     
-/**
- * Prints a brief statistic report about memory that reveals the following key values:
- * # total available memory in bytes.
- * # free (not allocated) memory in bytes.
- * # used (allocated) memory in bytes
- * # free memory in percentage (0 % to 100%)
- * # number of allocated units (continuously allocated portions of the memory, not memory blocks)
- * # largest free continuous memory unit in bytes.
- */
+    size_t freed_blocks = 0;
+    size_t i = start;
+    
+    while (i < MEMORY_BLOCK_CNT && memory[i] == 0xDEADBEEF) {
+        memory[i] = 0xAFFEBAFF;
+        freed_blocks++;
+        i++;
+    }
+    
+    freeBlocks += freed_blocks;
+    allocatedBlocks -= freed_blocks;
+}
+
 MemStat mem_get_statistics() {
-    return (MemStat){0, 0, 0, 0, 0, 0};
+    init_memory();
+    
+    MemStat stat;
+    stat.total_bytes = MEMORY_BLOCK_CNT * BYTES_PER_BLOCK;
+    stat.free_bytes = freeBlocks * BYTES_PER_BLOCK;
+    stat.used_bytes = allocatedBlocks * BYTES_PER_BLOCK;
+    stat.free_percentage = (double)stat.free_bytes / (double)stat.total_bytes * 100;
+    
+    size_t units_count = 0;
+    size_t i = 0;
+    
+    while (i < MEMORY_BLOCK_CNT) {
+        if (memory[i] == 0xDEADBEEF) {
+            units_count++;
+            while (i < MEMORY_BLOCK_CNT && memory[i] == 0xDEADBEEF) {
+                i++;
+            }
+        } else {
+            i++;
+        }
+    }
+    stat.allocated_units_count = units_count;
+    
+    size_t largest_free_unit = 0;
+    size_t current_free_unit = 0;
+    
+    for (i = 0; i < MEMORY_BLOCK_CNT; i++) {
+        if (memory[i] == 0xAFFEBAFF) {
+            current_free_unit++;
+        } else {
+            if (current_free_unit > largest_free_unit) {
+                largest_free_unit = current_free_unit;
+            }
+            current_free_unit = 0;
+        }
+    }
+
+    if (current_free_unit > largest_free_unit) {
+        largest_free_unit = current_free_unit;
+    }
+    
+    stat.larger_free_unit_bytes = largest_free_unit * BYTES_PER_BLOCK;
+    return stat;
 }
 
-/**
- * Prints the allocated units (continuously allocated portions of the memory, not memory blocks)
- * including their start address within the managed memory as well as their size
- * ordered by their start address.
- */
 void mem_print_units() {
-    return;
+    init_memory();
+    
+    size_t i = 0;
+    while (i < MEMORY_BLOCK_CNT) {
+        if (memory[i] == 0xDEADBEEF) {
+            size_t start = i;
+            size_t size = 0;
+            while (i < MEMORY_BLOCK_CNT && memory[i] == 0xDEADBEEF) {
+                size++;
+                i++;
+            }
+            printf("Allocated: Index %zu; Size: %zu\n", start, size);
+        } else {
+            i++;
+        }
+    }
 }
 
-/**
- * Provides the index of the allocated unit (continuously allocated portions of the memory, not memory blocks)
- * the addressed memory belongs to. If the addressed memory is not allocated or the address is outside
- * the range of the managed memory, a value less than zero provided.
- * 
- * @param p_mem The pointer to the memory to query.
- * @return The unit index the address belongs to or a value less than 0 if the memory is not allocated.
- */
 int get_unit_index(void *p_mem) {
-    return 0;
+    if (p_mem < (void*)memory || p_mem >= (void*)(memory + MEMORY_BLOCK_CNT)) {
+        return -1;
     }
     
-/**
- * Dumps the content of the memory.
- */
-void mem_dump() {
-    return;
+    int index = ((int*)p_mem - memory);
+    
+    if (memory[index] != 0xDEADBEEF) {
+        return -1;
+    }
+    
+    while (index > 0 && memory[index-1] == 0xDEADBEEF) {
+        index--;
+    }
+    
+    return index;
+}
+
+void mem_dump() {
+    init_memory();
+    
+    for (size_t i = 0; i < MEMORY_BLOCK_CNT; i++) {
+        printf("Memory: Index %zu; Content 0x%X\n", i, memory[i]);
+    }
 }