fix(C): fix array_hash_map.c and bucket_sort.c (#1272)

* fix: Fix coding error, https://github.com/krahets/hello-algo/discussions/440#discussioncomment-8958379

* fix: Fix issue 1237 https://github.com/krahets/hello-algo/issues/1237

* Update array_hash_map.c

* Update bucket_sort.c

* Update bucket_sort.c

* Update array_hash_map.c

* Update bucket_sort.c

* Update bucket_sort.c

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/c/chapter_hashing/array_hash_map.c

@@ -7,7 +7,7 @@
 #include "../utils/common.h"
 
 /* 哈希表默认大小 */
-#define HASHTABLE_CAPACITY 100
+#define MAX_SIZE 100
 
 /* 键值对 int->string */
 typedef struct {
@@ -23,18 +23,21 @@ typedef struct {
 
 /* 基于数组实现的哈希表 */
 typedef struct {
-    Pair *buckets[HASHTABLE_CAPACITY];
+    Pair *buckets[MAX_SIZE];
 } ArrayHashMap;
 
 /* 构造函数 */
 ArrayHashMap *newArrayHashMap() {
     ArrayHashMap *hmap = malloc(sizeof(ArrayHashMap));
+    for (int i=0; i < MAX_SIZE; i++) {
+        hmap->buckets[i] = NULL;
+    }
     return hmap;
 }
 
 /* 析构函数 */
 void delArrayHashMap(ArrayHashMap *hmap) {
-    for (int i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (int i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             free(hmap->buckets[i]->val);
             free(hmap->buckets[i]);
@@ -45,7 +48,7 @@ void delArrayHashMap(ArrayHashMap *hmap) {
 
 /* 哈希函数 */
 int hashFunc(int key) {
-    int index = key % HASHTABLE_CAPACITY;
+    int index = key % MAX_SIZE;
     return index;
 }
 
@@ -83,13 +86,13 @@ void pairSet(ArrayHashMap *hmap, MapSet *set) {
     int i = 0, index = 0;
     int total = 0;
     /* 统计有效键值对数量 */
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             total++;
         }
     }
     entries = malloc(sizeof(Pair) * total);
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             entries[index].key = hmap->buckets[i]->key;
             entries[index].val = malloc(strlen(hmap->buckets[i]->val) + 1);
@@ -107,13 +110,13 @@ void keySet(ArrayHashMap *hmap, MapSet *set) {
     int i = 0, index = 0;
     int total = 0;
     /* 统计有效键值对数量 */
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             total++;
         }
     }
     keys = malloc(total * sizeof(int));
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             keys[index] = hmap->buckets[i]->key;
             index++;
@@ -129,13 +132,13 @@ void valueSet(ArrayHashMap *hmap, MapSet *set) {
     int i = 0, index = 0;
     int total = 0;
     /* 统计有效键值对数量 */
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             total++;
         }
     }
     vals = malloc(total * sizeof(char *));
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             vals[index] = hmap->buckets[i]->val;
             index++;

codes/c/chapter_sorting/bucket_sort.c

@@ -8,66 +8,45 @@
 
 #define SIZE 10
 
-/* 比较两个浮点数的大小 */
+/* 用于 qsort 的比较函数 */
-int compare_float(const void *a, const void *b) {
+int compare(const void *a, const void *b) {
     float fa = *(const float *)a;
     float fb = *(const float *)b;
     return (fa > fb) - (fa < fb);
 }
 
-/* 交换两个浮点数 */
-void swap(float *a, float *b) {
-    float tmp = *a;
-    *a = *b;
-    *b = tmp;
-}
-
 /* 桶排序 */
-void bucketSort(float nums[], int size) {
+void bucketSort(float nums[], int n) {
-    // 初始化 k = n/2 个桶，预期向每个桶分配 2 个元素
+    int k = n / 2;                                 // 初始化 k = n/2 个桶
-    int k = size / 2;
+    int *sizes = malloc(k * sizeof(int));          // 记录每个桶的大小
-    float **buckets = calloc(k, sizeof(float *));
+    float **buckets = malloc(k * sizeof(float *)); // 动态数组的数组（桶）
-    for (int i = 0; i < k; i++) {
+
-        // 每个桶最多可以分配 size 个元素
+    for (int i = 0; i < k; ++i) {
-        buckets[i] = calloc(size, sizeof(float));
+        // 为每个桶预分配足够的空间
+        buckets[i] = (float *)malloc(n * sizeof(float));
+        sizes[i] = 0;
     }
 
     // 1. 将数组元素分配到各个桶中
-    for (int i = 0; i < size; i++) {
+    for (int i = 0; i < n; ++i) {
-        // 输入数据范围为 [0, 1)，使用 num * k 映射到索引范围 [0, k-1]
+        int idx = (int)(nums[i] * k);
-        int bucket_idx = nums[i] * k;
+        buckets[idx][sizes[idx]++] = nums[i];
-        int j = 0;
-        // 如果桶中有数据且数据小于当前值 nums[i], 要将其放到当前桶的后面，相当于 cpp 中的 push_back
-        while (buckets[bucket_idx][j] > 0 && buckets[bucket_idx][j] < nums[i]) {
-            j++;
-        }
-        float temp = nums[i];
-        while (j < size && buckets[bucket_idx][j] > 0) {
-            swap(&temp, &buckets[bucket_idx][j]);
-            j++;
-        }
-        buckets[bucket_idx][j] = temp;
     }
 
     // 2. 对各个桶执行排序
-    for (int i = 0; i < k; i++) {
+    for (int i = 0; i < k; ++i) {
-        qsort(buckets[i], size, sizeof(float), compare_float);
+        qsort(buckets[i], sizes[i], sizeof(float), compare);
     }
 
-    // 3. 遍历桶合并结果
+    // 3. 合并排序后的桶
-    for (int i = 0, j = 0; j < k; j++) {
+    int idx = 0;
-        for (int l = 0; l < size; l++) {
+    for (int i = 0; i < k; ++i) {
-            if (buckets[j][l] > 0) {
+        for (int j = 0; j < sizes[i]; ++j) {
-                nums[i++] = buckets[j][l];
+            nums[idx++] = buckets[i][j];
-            }
         }
-    }
+        // 释放内存
-
-    // 释放上述分配的内存
-    for (int i = 0; i < k; i++) {
         free(buckets[i]);
     }
-    free(buckets);
 }
 
 /* Driver Code */
@@ -79,4 +58,4 @@ int main() {
     printArrayFloat(nums, SIZE);
 
     return 0;
-}
+}

zh-hant/codes/c/chapter_hashing/array_hash_map.c

@@ -7,7 +7,7 @@
 #include "../utils/common.h"
 
 /* 雜湊表預設大小 */
-#define HASHTABLE_CAPACITY 100
+#define  100
 
 /* 鍵值對 int->string */
 typedef struct {
@@ -23,18 +23,21 @@ typedef struct {
 
 /* 基於陣列實現的雜湊表 */
 typedef struct {
-    Pair *buckets[HASHTABLE_CAPACITY];
+    Pair *buckets[MAX_SIZE];
 } ArrayHashMap;
 
 /* 建構子 */
 ArrayHashMap *newArrayHashMap() {
     ArrayHashMap *hmap = malloc(sizeof(ArrayHashMap));
+    for (int i = 0; i < MAX_SIZE; i++) {
+        hmap->buckets[i] = NULL;
+    }
     return hmap;
 }
 
 /* 析構函式 */
 void delArrayHashMap(ArrayHashMap *hmap) {
-    for (int i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (int i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             free(hmap->buckets[i]->val);
             free(hmap->buckets[i]);
@@ -45,7 +48,7 @@ void delArrayHashMap(ArrayHashMap *hmap) {
 
 /* 雜湊函式 */
 int hashFunc(int key) {
-    int index = key % HASHTABLE_CAPACITY;
+    int index = key % MAX_SIZE;
     return index;
 }
 
@@ -83,13 +86,13 @@ void pairSet(ArrayHashMap *hmap, MapSet *set) {
     int i = 0, index = 0;
     int total = 0;
     /* 統計有效鍵值對數量 */
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             total++;
         }
     }
     entries = malloc(sizeof(Pair) * total);
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             entries[index].key = hmap->buckets[i]->key;
             entries[index].val = malloc(strlen(hmap->buckets[i]->val) + 1);
@@ -107,13 +110,13 @@ void keySet(ArrayHashMap *hmap, MapSet *set) {
     int i = 0, index = 0;
     int total = 0;
     /* 統計有效鍵值對數量 */
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             total++;
         }
     }
     keys = malloc(total * sizeof(int));
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             keys[index] = hmap->buckets[i]->key;
             index++;
@@ -129,13 +132,13 @@ void valueSet(ArrayHashMap *hmap, MapSet *set) {
     int i = 0, index = 0;
     int total = 0;
     /* 統計有效鍵值對數量 */
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             total++;
         }
     }
     vals = malloc(total * sizeof(char *));
-    for (i = 0; i < HASHTABLE_CAPACITY; i++) {
+    for (i = 0; i < MAX_SIZE; i++) {
         if (hmap->buckets[i] != NULL) {
             vals[index] = hmap->buckets[i]->val;
             index++;

zh-hant/codes/c/chapter_sorting/bucket_sort.c

@@ -8,66 +8,45 @@
 
 #define SIZE 10
 
-/* 比較兩個浮點數的大小 */
+/* 用於 qsort 的比較函式 */
-int compare_float(const void *a, const void *b) {
+int compare(const void *a, const void *b) {
     float fa = *(const float *)a;
     float fb = *(const float *)b;
     return (fa > fb) - (fa < fb);
 }
 
-/* 交換兩個浮點數 */
-void swap(float *a, float *b) {
-    float tmp = *a;
-    *a = *b;
-    *b = tmp;
-}
-
 /* 桶排序 */
-void bucketSort(float nums[], int size) {
+void bucketSort(float nums[], int n) {
-    // 初始化 k = n/2 個桶，預期向每個桶分配 2 個元素
+    int k = n / 2;                                 // 初始化 k = n/2 個桶
-    int k = size / 2;
+    int *sizes = malloc(k * sizeof(int));          // 記錄每個桶的大小
-    float **buckets = calloc(k, sizeof(float *));
+    float **buckets = malloc(k * sizeof(float *)); // 動態陣列的陣列（桶）
-    for (int i = 0; i < k; i++) {
+
-        // 每個桶最多可以分配 size 個元素
+    for (int i = 0; i < k; ++i) {
-        buckets[i] = calloc(size, sizeof(float));
+        // 為每個桶預分配足夠的空間
+        buckets[i] = (float *)malloc(n * sizeof(float));
+        sizes[i] = 0;
     }
 
     // 1. 將陣列元素分配到各個桶中
-    for (int i = 0; i < size; i++) {
+    for (int i = 0; i < n; ++i) {
-        // 輸入資料範圍為 [0, 1)，使用 num * k 對映到索引範圍 [0, k-1]
+        int idx = (int)(nums[i] * k);
-        int bucket_idx = nums[i] * k;
+        buckets[idx][sizes[idx]++] = nums[i];
-        int j = 0;
-        // 如果桶中有資料且資料小於當前值 nums[i], 要將其放到當前桶的後面，相當於 cpp 中的 push_back
-        while (buckets[bucket_idx][j] > 0 && buckets[bucket_idx][j] < nums[i]) {
-            j++;
-        }
-        float temp = nums[i];
-        while (j < size && buckets[bucket_idx][j] > 0) {
-            swap(&temp, &buckets[bucket_idx][j]);
-            j++;
-        }
-        buckets[bucket_idx][j] = temp;
     }
 
     // 2. 對各個桶執行排序
-    for (int i = 0; i < k; i++) {
+    for (int i = 0; i < k; ++i) {
-        qsort(buckets[i], size, sizeof(float), compare_float);
+        qsort(buckets[i], sizes[i], sizeof(float), compare);
     }
 
-    // 3. 走訪桶合併結果
+    // 3. 合併排序後的桶
-    for (int i = 0, j = 0; j < k; j++) {
+    int idx = 0;
-        for (int l = 0; l < size; l++) {
+    for (int i = 0; i < k; ++i) {
-            if (buckets[j][l] > 0) {
+        for (int j = 0; j < sizes[i]; ++j) {
-                nums[i++] = buckets[j][l];
+            nums[idx++] = buckets[i][j];
-            }
         }
-    }
+        // 釋放記憶體
-
-    // 釋放上述分配的記憶體
-    for (int i = 0; i < k; i++) {
         free(buckets[i]);
     }
-    free(buckets);
 }
 
 /* Driver Code */
@@ -79,4 +58,4 @@ int main() {
     printArrayFloat(nums, SIZE);
 
     return 0;
-}
+}