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

Browse source 
* 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>
This commit is contained in:
Lanjing Gong 2024-04-12 03:03:18 +08:00 committed by GitHub
parent 49e6a208f6
commit aca850244b
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GPG key ID: B5690EEEBB952194
4 changed files with 72 additions and 108 deletions
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23
codes/c/chapter_hashing/array_hash_map.c
View file

@ -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++;

67
codes/c/chapter_sorting/bucket_sort.c
View file

@ -8,66 +8,45 @@
#define SIZE 10
/* 比较两个浮点数的大小 */
int compare_float(const void *a, const void *b) {
/* 用于 qsort 的比较函数 */
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) {
// 初始化 k = n/2 个桶，预期向每个桶分配 2 个元素
int k = size / 2;
float **buckets = calloc(k, sizeof(float *));
for (int i = 0; i < k; i++) {
// 每个桶最多可以分配 size 个元素
buckets[i] = calloc(size, sizeof(float));
void bucketSort(float nums[], int n) {
int k = n / 2; // 初始化 k = n/2 个桶
int *sizes = malloc(k * sizeof(int)); // 记录每个桶的大小
float **buckets = malloc(k * sizeof(float *)); // 动态数组的数组（桶）
for (int i = 0; i < k; ++i) {
// 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++) {
// 输入数据范围为 [0, 1)，使用 num * k 映射到索引范围 [0, k-1]
int bucket_idx = nums[i] * k;
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;
for (int i = 0; i < n; ++i) {
int idx = (int)(nums[i] * k);
buckets[idx][sizes[idx]++] = nums[i];
}
// 2. 对各个桶执行排序
for (int i = 0; i < k; i++) {
qsort(buckets[i], size, sizeof(float), compare_float);
for (int i = 0; i < k; ++i) {
qsort(buckets[i], sizes[i], sizeof(float), compare);
}
// 3. 遍历桶合并结果
for (int i = 0, j = 0; j < k; j++) {
for (int l = 0; l < size; l++) {
if (buckets[j][l] > 0) {
nums[i++] = buckets[j][l];
}
// 3. 合并排序后的桶
int idx = 0;
for (int i = 0; i < k; ++i) {
for (int j = 0; j < sizes[i]; ++j) {
nums[idx++] = buckets[i][j];
}
}
// 释放上述分配的内存
for (int i = 0; i < k; i++) {
// 释放内存
free(buckets[i]);
}
free(buckets);
}
/* Driver Code */
@ -79,4 +58,4 @@ int main() {
printArrayFloat(nums, SIZE);
return 0;
}
}

23
zh-hant/codes/c/chapter_hashing/array_hash_map.c
View file

@ -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++;

67
zh-hant/codes/c/chapter_sorting/bucket_sort.c
View file

@ -8,66 +8,45 @@
#define SIZE 10
/* 比較兩個浮點數的大小 */
int compare_float(const void *a, const void *b) {
/* 用於 qsort 的比較函式 */
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) {
// 初始化 k = n/2 個桶，預期向每個桶分配 2 個元素
int k = size / 2;
float **buckets = calloc(k, sizeof(float *));
for (int i = 0; i < k; i++) {
// 每個桶最多可以分配 size 個元素
buckets[i] = calloc(size, sizeof(float));
void bucketSort(float nums[], int n) {
int k = n / 2; // 初始化 k = n/2 個桶
int *sizes = malloc(k * sizeof(int)); // 記錄每個桶的大小
float **buckets = malloc(k * sizeof(float *)); // 動態陣列的陣列（桶）
for (int i = 0; i < k; ++i) {
// 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++) {
// 輸入資料範圍為 [0, 1)，使用 num * k 對映到索引範圍 [0, k-1]
int bucket_idx = nums[i] * k;
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;
for (int i = 0; i < n; ++i) {
int idx = (int)(nums[i] * k);
buckets[idx][sizes[idx]++] = nums[i];
}
// 2. 對各個桶執行排序
for (int i = 0; i < k; i++) {
qsort(buckets[i], size, sizeof(float), compare_float);
for (int i = 0; i < k; ++i) {
qsort(buckets[i], sizes[i], sizeof(float), compare);
}
// 3. 走訪桶合併結果
for (int i = 0, j = 0; j < k; j++) {
for (int l = 0; l < size; l++) {
if (buckets[j][l] > 0) {
nums[i++] = buckets[j][l];
}
// 3. 合併排序後的桶
int idx = 0;
for (int i = 0; i < k; ++i) {
for (int j = 0; j < sizes[i]; ++j) {
nums[idx++] = buckets[i][j];
}
}
// 釋放上述分配的記憶體
for (int i = 0; i < k; i++) {
// 釋放記憶體
free(buckets[i]);
}
free(buckets);
}
/* Driver Code */
@ -79,4 +58,4 @@ int main() {
printArrayFloat(nums, SIZE);
return 0;
}
}