From 86209e0a7b6f42bc08c4a57b741ae7f89a9d472d Mon Sep 17 00:00:00 2001 From: gonglja <39959756+Gonglja@users.noreply.github.com> Date: Fri, 2 Jun 2023 02:51:35 +0800 Subject: [PATCH] feat: Add C codes for bucket sort, heap sort, selection sort, binary search edge (#525) * fix(codes/cpp): Memory leak fix: the space was not freed when pop removed the element. * fix(codes/cpp): Fix access error when printArray(arr, 0) * Update PrintUtil.hpp * fix(codes/c): Fix some errors of cmake build * feat(codes/c): Add hashing_search.c * styles(codes/c): Modify function description * styles(codes/c): Modify binary_search.c code style * fix(codes/c): Fix the problem in binary_tree_bfs.c and the problem that the memory is not released. * feat: Add preorder_traversal_i_compact.c * feat(codes/c): Add head_sort.c * feat(codes/c): Add bucket_sort.c * feat(codes/c): Add binary_search_edge.c * fix(codes/c): Add programs that are not managed by cmake (c code) * feat(codes/c): Add selection_sort.c * style(codes/c): Change swap in selection_sort.c to `selectionSort` * styles(codes/c): Change style. * fix(codes/c): Fix some formatting errors and temporarily remove backtracking chapters --------- Co-authored-by: Yudong Jin --- codes/c/CMakeLists.txt | 3 +- codes/c/chapter_searching/CMakeLists.txt | 5 +- .../c/chapter_searching/binary_search_edge.c | 59 +++++++++++++ codes/c/chapter_sorting/CMakeLists.txt | 3 + codes/c/chapter_sorting/bucket_sort.c | 82 +++++++++++++++++++ codes/c/chapter_sorting/heap_sort.c | 60 ++++++++++++++ codes/c/chapter_sorting/selection_sort.c | 37 +++++++++ codes/c/utils/print_util.h | 21 +++++ 8 files changed, 268 insertions(+), 2 deletions(-) create mode 100644 codes/c/chapter_searching/binary_search_edge.c create mode 100644 codes/c/chapter_sorting/bucket_sort.c create mode 100644 codes/c/chapter_sorting/heap_sort.c create mode 100644 codes/c/chapter_sorting/selection_sort.c diff --git a/codes/c/CMakeLists.txt b/codes/c/CMakeLists.txt index a1cc1d3c7..030d2f93f 100644 --- a/codes/c/CMakeLists.txt +++ b/codes/c/CMakeLists.txt @@ -12,4 +12,5 @@ add_subdirectory(chapter_heap) add_subdirectory(chapter_hashing) add_subdirectory(chapter_tree) add_subdirectory(chapter_searching) -add_subdirectory(chapter_sorting) \ No newline at end of file +add_subdirectory(chapter_sorting) +add_subdirectory(chapter_backtracking) \ No newline at end of file diff --git a/codes/c/chapter_searching/CMakeLists.txt b/codes/c/chapter_searching/CMakeLists.txt index 6cdf80622..8282333ab 100644 --- a/codes/c/chapter_searching/CMakeLists.txt +++ b/codes/c/chapter_searching/CMakeLists.txt @@ -1,2 +1,5 @@ add_executable(binary_search binary_search.c) -add_executable(two_sum two_sum.c) \ No newline at end of file +add_executable(two_sum two_sum.c) +add_executable(binary_search_edge binary_search_edge.c) +add_executable(hashing_search hashing_search.c) +add_executable(linear_search linear_search.c) \ No newline at end of file diff --git a/codes/c/chapter_searching/binary_search_edge.c b/codes/c/chapter_searching/binary_search_edge.c new file mode 100644 index 000000000..077317ca0 --- /dev/null +++ b/codes/c/chapter_searching/binary_search_edge.c @@ -0,0 +1,59 @@ +/** + * File: binary_search_edge.c + * Created Time: 2023-05-31 + * Author: Gonglja (glj0@outlook.com) + */ + +#include "../utils/common.h" + + +/* 二分查找最左一个元素 */ +int binarySearchLeftEdge(int *nums, int size, int target) { + int i = 0, j = size - 1; // 初始化双闭区间 [0, n-1] + while (i <= j) { + int m = i + (j - i) / 2; // 计算中点索引 m + if (nums[m] < target) + i = m + 1; // target 在区间 [m+1, j] 中 + else if (nums[m] > target) + j = m - 1; // target 在区间 [i, m-1] 中 + else + j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中 + } + if (i == size || nums[i] != target) + return -1; // 未找到目标元素，返回 -1 + return i; +} + +/* 二分查找最右一个元素 */ +int binarySearchRightEdge(int *nums, int size, int target) { + int i = 0, j = size - 1; // 初始化双闭区间 [0, n-1] + while (i <= j) { + int m = i + (j - i) / 2; // 计算中点索引 m + if (nums[m] < target) + i = m + 1; // target 在区间 [m+1, j] 中 + else if (nums[m] > target) + j = m - 1; // target 在区间 [i, m-1] 中 + else + i = m + 1; // 首个大于 target 的元素在区间 [m+1, j] 中 + } + if (j < 0 || nums[j] != target) + return -1; // 未找到目标元素，返回 -1 + return j; +} + +/* Driver Code */ +int main() { + int target = 6; + int nums[] = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15}; + int size = sizeof(nums) / sizeof(nums[0]); + + // 二分查找最左一个元素 + int indexLeft = binarySearchLeftEdge(nums, size, target); + printf("数组中最左一个元素 6 的索引 = %d\n", indexLeft); + + // 二分查找最右一个元素 + int indexRight = binarySearchRightEdge(nums, size, target); + printf("数组中最右一个元素 6 的索引 = %d\n", indexRight); + + return 0; +} \ No newline at end of file diff --git a/codes/c/chapter_sorting/CMakeLists.txt b/codes/c/chapter_sorting/CMakeLists.txt index bbe2d9b31..88756b4c9 100644 --- a/codes/c/chapter_sorting/CMakeLists.txt +++ b/codes/c/chapter_sorting/CMakeLists.txt @@ -4,3 +4,6 @@ add_executable(quick_sort quick_sort.c) add_executable(counting_sort counting_sort.c) add_executable(radix_sort radix_sort.c) add_executable(merge_sort merge_sort.c) +add_executable(heap_sort heap_sort.c) +add_executable(bucket_sort bucket_sort.c) +add_executable(selection_sort selection_sort.c) diff --git a/codes/c/chapter_sorting/bucket_sort.c b/codes/c/chapter_sorting/bucket_sort.c new file mode 100644 index 000000000..019027a10 --- /dev/null +++ b/codes/c/chapter_sorting/bucket_sort.c @@ -0,0 +1,82 @@ +/** + * File: bucket_sort.c + * Created Time: 2023-05-30 + * Author: Gonglja (glj0@outlook.com) + */ + +#include "../utils/common.h" + +#define ARRAY_SIZE 10 + +/* 比较两个浮点数的大小 */ +int compare_float(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 k 个元素 + buckets[i] = calloc(ARRAY_SIZE, sizeof(float)); + } + + // 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 [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 < ARRAY_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++) { + qsort(buckets[i], ARRAY_SIZE, sizeof(float), compare_float); + } + + // 3. 遍历桶合并结果 + for (int i = 0, j = 0; j < k; j++) { + for (int l = 0; l < ARRAY_SIZE; l++) { + if (buckets[j][l] > 0) { + nums[i++] = buckets[j][l]; + } + } + } + + // 释放上述分配的内存 + for (int i = 0; i < k; i++) { + free(buckets[i]); + } + free(buckets); +} + +/* Driver Code */ +int main() { + // 设输入数据为浮点数，范围为 [0, 1) + float nums[ARRAY_SIZE] = {0.49f, 0.96f, 0.82f, 0.09f, 0.57f, 0.43f, 0.91f, 0.75f, 0.15f, 0.37f}; + bucketSort(nums, ARRAY_SIZE); + printf("桶排序完成后 nums = "); + printArrayFloat(nums, ARRAY_SIZE); + + return 0; +} \ No newline at end of file diff --git a/codes/c/chapter_sorting/heap_sort.c b/codes/c/chapter_sorting/heap_sort.c new file mode 100644 index 000000000..084aa0a5b --- /dev/null +++ b/codes/c/chapter_sorting/heap_sort.c @@ -0,0 +1,60 @@ +/** + * File: heap_sort.c + * Created Time: 2023-05-30 + * Author: Gonglja (glj0@outlook.com) + */ + +#include "../utils/common.h" + +/* 堆的长度为 n ，从节点 i 开始，从顶至底堆化 */ +void siftDown(int nums[], int n, int i) { + while (1) { + // 判断节点 i, l, r 中值最大的节点，记为 ma + int l = 2 * i + 1; + int r = 2 * i + 2; + int ma = i; + if (l < n && nums[l] > nums[ma]) + ma = l; + if (r < n && nums[r] > nums[ma]) + ma = r; + // 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出 + if (ma == i) { + break; + } + // 交换两节点 + int temp = nums[i]; + nums[i] = nums[ma]; + nums[ma] = temp; + // 循环向下堆化 + i = ma; + } +} + +/* 堆排序 */ +void heapSort(int nums[], int n) { + // 建堆操作：堆化除叶节点以外的其他所有节点 + for (int i = n / 2 - 1; i >= 0; --i) { + siftDown(nums, n, i); + } + // 从堆中提取最大元素，循环 n-1 轮 + for (int i = n - 1; i > 0; --i) { + // 交换根节点与最右叶节点（即交换首元素与尾元素） + int tmp = nums[0]; + nums[0] = nums[i]; + nums[i] = tmp; + // 以根节点为起点，从顶至底进行堆化 + siftDown(nums, i, 0); + } +} + +/* Driver Code */ +int main() { + int nums[] = {4, 1, 3, 1, 5, 2}; + int n = sizeof(nums) / sizeof(nums[0]); + + heapSort(nums, n); + printf("堆排序完成后 nums = "); + printArray(nums, n); + + return 0; +} \ No newline at end of file diff --git a/codes/c/chapter_sorting/selection_sort.c b/codes/c/chapter_sorting/selection_sort.c new file mode 100644 index 000000000..d80d804ca --- /dev/null +++ b/codes/c/chapter_sorting/selection_sort.c @@ -0,0 +1,37 @@ +/** + * File: selection_sort.c + * Created Time: 2023-05-31 + * Author: Gonglja (glj0@outlook.com) + */ + +#include "../utils/common.h" + +/* 选择排序 */ +void selectionSort(int nums[], int n) { + // 外循环：未排序区间为 [i, n-1] + for (int i = 0; i < n - 1; i++) { + // 内循环：找到未排序区间内的最小元素 + int k = i; + for (int j = i + 1; j < n; j++) { + if (nums[j] < nums[k]) + k = j; // 记录最小元素的索引 + } + // 将该最小元素与未排序区间的首个元素交换 + int temp = nums[i]; + nums[i] = nums[k]; + nums[k] = temp; + } +} + +/* 主函数 */ +int main() { + int nums[] = {4, 1, 3, 1, 5, 2}; + int n = sizeof(nums) / sizeof(nums[0]); + + selectionSort(nums, n); + + printf("选择排序完成后 nums = "); + printArray(nums, n); + + return 0; +} diff --git a/codes/c/utils/print_util.h b/codes/c/utils/print_util.h index fa0302ceb..e135c6201 100644 --- a/codes/c/utils/print_util.h +++ b/codes/c/utils/print_util.h @@ -39,6 +39,27 @@ static void printArray(int arr[], int size) { } } +/* Print an Array */ +static void printArrayFloat(float arr[], int size) { + printf("["); + if (arr != NULL && size != 0) { + for (int i = 0; i < size - 1; i++) { + if (arr[i] != INT_MAX) { + printf("%.2f, ", arr[i]); + } else { + printf("NULL, "); + } + } + if (arr[size - 1] != INT_MAX) { + printf("%.2f]\n", arr[size - 1]); + } else { + printf("NULL]\n"); + } + } else { + printf("]"); + } +} + /* Print a linked list */ static void printLinkedList(ListNode *node) { if (node == NULL) {