This commit is contained in:
krahets
2024-04-12 03:16:45 +08:00
parent 8b8168bb31
commit b5f94abec9
10 changed files with 217 additions and 101 deletions

View File

@ -340,51 +340,37 @@ comments: true
```c title="bucket_sort.c"
/* 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);
}
```