Add interation.c recursion.c simple_hash.c binary_search_edge.c binary_search_insertion.c in C codes. (#731)

* 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

* fix(codes/c): Fix space_complexity.c build error.

* feat(codes/c): Add array_binary_tree.c

* feat(code/c): Update push_back and pop_back in vector.h

* styles(codes/c): Adjust  format.

* feat(codes/c): Add `interation.c ` `recursion.c` `simple_hash.c` `binary_search_edge.c` `binary_search_insertion.c` in C codes.

---------

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

codes/c/chapter_computational_complexity/CMakeLists.txt

@@ -1,3 +1,5 @@
 add_executable(time_complexity time_complexity.c)
 add_executable(worst_best_time_complexity worst_best_time_complexity.c)
 add_executable(space_complexity space_complexity.c)
+add_executable(iteration iteration.c)
+add_executable(recursion recursion.c)

codes/c/chapter_computational_complexity/iteration.c

@@ -0,0 +1,82 @@
+/**
+ * File: iteration.c
+ * Created Time: 2023-09-09
+ * Author: Gonglja (glj0@outlook.com)
+ */
+
+#include "../utils/common.h"
+
+/* for 循环 */
+int forLoop(int n) {
+    int res = 0;
+    // 循环求和 1, 2, ..., n-1, n
+    for (int i = 1; i <= n; ++i) {
+        res += i;
+    }
+    return res;
+}
+
+/* while 循环 */
+int whileLoop(int n) {
+    int res = 0;
+    int i = 1; // 初始化条件变量
+    // 循环求和 1, 2, ..., n-1, n
+    while (i <= n) {
+        res += i;
+        i++; // 更新条件变量
+    }
+    return res;
+}
+
+/* while 循环（两次更新） */
+int whileLoopII(int n) {
+    int res = 0;
+    int i = 1; // 初始化条件变量
+    // 循环求和 1, 4, ...
+    while (i <= n) {
+        res += i;
+        // 更新条件变量
+        i++;
+        i *= 2;
+    }
+    return res;
+}
+
+/* 双层 for 循环 */
+char *nestedForLoop(int n) {
+    // n * n 为对应点数量，"(i, j), " 对应字符串长最大为 6+10*2，加上最后一个空字符 \0 的额外空间
+    int size = n * n * 26 + 1;
+    char *res = malloc(size * sizeof(char));
+
+    // 循环 i = 1, 2, ..., n-1, n
+    for (int i = 1; i <= n; ++i) {
+        // 循环 j = 1, 2, ..., n-1, n
+        for (int j = 1; j <= n; ++j) {
+            char tmp[26];
+            snprintf(tmp, sizeof(tmp), "(%d, %d), ", i, j);
+            strncat(res, tmp, size - strlen(res) - 1);
+        }
+    }
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    int n = 5;
+    int res;
+
+    res = forLoop(n);
+    printf("\nfor 循环的求和结果 res = %d\n", res);
+
+    res = whileLoop(n);
+    printf("\nwhile 循环的求和结果 res = %d\n", res);
+
+    res = whileLoopII(n);
+    printf("\nwhile 循环（两次更新）求和结果 res = %d\n", res);
+
+    char *resStr = nestedForLoop(n);
+    printf("\n双层 for 循环的遍历结果 %s\r\n", resStr);
+    free(resStr);
+
+    return 0;
+}

codes/c/chapter_computational_complexity/recursion.c

@@ -0,0 +1,55 @@
+/**
+ * File: recursion.c
+ * Created Time: 2023-09-09
+ * Author: Gonglja (glj0@outlook.com)
+ */
+
+#include "../utils/common.h"
+
+/* 递归 */
+int recur(int n) {
+    // 终止条件
+    if (n == 1)
+        return 1;
+    // 递：递归调用
+    int res = recur(n - 1);
+    // 归：返回结果
+    return n + res;
+}
+
+/* 尾递归 */
+int tailRecur(int n, int res) {
+    // 终止条件
+    if (n == 0)
+        return res;
+    // 尾递归调用
+    return tailRecur(n - 1, res + n);
+}
+
+/* 斐波那契数列：递归 */
+int fib(int n) {
+    // 终止条件 f(1) = 0, f(2) = 1
+    if (n == 1 || n == 2)
+        return n - 1;
+    // 递归调用 f(n) = f(n-1) + f(n-2)
+    int res = fib(n - 1) + fib(n - 2);
+    // 返回结果 f(n)
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    int n = 5;
+    int res;
+
+    res = recur(n);
+    printf("\n递归函数的求和结果 res = %d\n", res);
+
+    res = tailRecur(n, 0);
+    printf("\n尾递归函数的求和结果 res = %d\n", res);
+
+    res = fib(n);
+    printf("\n斐波那契数列的第 %d 项为 %d\n", n, res);
+
+    return 0;
+}

codes/c/chapter_hashing/CMakeLists.txt

@@ -1,2 +1,3 @@
 add_executable(array_hash_map array_hash_map.c)
+add_executable(simple_hash simple_hash.c)
 

codes/c/chapter_hashing/simple_hash.c

@@ -0,0 +1,68 @@
+/**
+ * File: simple_hash.c
+ * Created Time: 2023-09-09
+ * Author: Gonglja (glj0@outlook.com)
+ */
+
+#include "../utils/common.h"
+
+/* 加法哈希 */
+int addHash(char *key) {
+    long long hash = 0;
+    const int MODULUS = 1000000007;
+    for (int i = 0; i < strlen(key); i++) {
+        hash = (hash + (unsigned char)key[i]) % MODULUS;
+    }
+    return (int)hash;
+}
+
+/* 乘法哈希 */
+int mulHash(char *key) {
+    long long hash = 0;
+    const int MODULUS = 1000000007;
+    for (int i = 0; i < strlen(key); i++) {
+        hash = (31 * hash + (unsigned char)key[i]) % MODULUS;
+    }
+    return (int)hash;
+}
+
+/* 异或哈希 */
+int xorHash(char *key) {
+    int hash = 0;
+    const int MODULUS = 1000000007;
+
+    for (int i = 0; i < strlen(key); i++) {
+        hash ^= (unsigned char)key[i];
+    }
+    return hash & MODULUS;
+}
+
+/* 旋转哈希 */
+int rotHash(char *key) {
+    long long hash = 0;
+    const int MODULUS = 1000000007;
+    for (int i = 0; i < strlen(key); i++) {
+        hash = ((hash << 4) ^ (hash >> 28) ^ (unsigned char)key[i]) % MODULUS;
+    }
+
+    return (int)hash;
+}
+
+/* Driver Code */
+int main() {
+    char *key = "Hello dsad3241241dsa算123法";
+
+    int hash = addHash(key);
+    printf("加法哈希值为 %d\n", hash);
+
+    hash = mulHash(key);
+    printf("乘法哈希值为 %d\n", hash);
+
+    hash = xorHash(key);
+    printf("异或哈希值为 %d\n", hash);
+
+    hash = rotHash(key);
+    printf("旋转哈希值为 %d\n", hash);
+
+    return 0;
+}

codes/c/chapter_searching/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_executable(binary_search binary_search.c)
 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)
+add_executable(binary_search_edge binary_search_edge.c)
+add_executable(binary_search_insertion binary_search_insertion.c)

codes/c/chapter_searching/binary_search_edge.c

@@ -0,0 +1,66 @@
+/**
+ * File: binary_search_edge.c
+ * Created Time: 2023-09-09
+ * Author: Gonglja (glj0@outlook.com)
+ */
+
+#include "../utils/common.h"
+
+/* 二分查找插入点（存在重复元素） */
+int binarySearchInsertion(int *nums, int numSize, int target) {
+    int i = 0, j = numSize - 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 {
+            j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
+        }
+    }
+    // 返回插入点 i
+    return i;
+}
+
+/* 二分查找最左一个 target */
+int binarySearchLeftEdge(int *nums, int numSize, int target) {
+    // 等价于查找 target 的插入点
+    int i = binarySearchInsertion(nums, numSize, target);
+    // 未找到 target ，返回 -1
+    if (i == numSize || nums[i] != target) {
+        return -1;
+    }
+    // 找到 target ，返回索引 i
+    return i;
+}
+
+/* 二分查找最右一个 target */
+int binarySearchRightEdge(int *nums, int numSize, int target) {
+    // 转化为查找最左一个 target + 1
+    int i = binarySearchInsertion(nums, numSize, target + 1);
+    // j 指向最右一个 target ，i 指向首个大于 target 的元素
+    int j = i - 1;
+    // 未找到 target ，返回 -1
+    if (j == -1 || nums[j] != target) {
+        return -1;
+    }
+    // 找到 target ，返回索引 j
+    return j;
+}
+
+/* Driver Code */
+int main() {
+    // 包含重复元素的数组
+    int nums[] = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15};
+    printf("\n数组 nums = ");
+    printArray(nums, sizeof(nums) / sizeof(nums[0]));
+
+    // 二分查找左边界和右边界
+    int targets[] = {6, 7};
+    for (int i = 0; i < sizeof(targets) / sizeof(targets[0]); i++) {
+        int index = binarySearchLeftEdge(nums, sizeof(nums) / sizeof(nums[0]), targets[i]);
+        printf("最左一个元素 %d 的索引为 %d\n", targets[i], index);
+        index = binarySearchRightEdge(nums, sizeof(nums) / sizeof(nums[0]), targets[i]);
+        printf("最右一个元素 %d 的索引为 %d\n", targets[i], index);
+    }
+    return 0;
+}

codes/c/chapter_searching/binary_search_insertion.c

@@ -0,0 +1,68 @@
+/**
+ * File: binary_search_insertion.c
+ * Created Time: 2023-09-09
+ * Author: Gonglja (glj0@outlook.com)
+ */
+
+#include "../utils/common.h"
+
+/* 二分查找插入点（无重复元素） */
+int binarySearchInsertionSimple(int *nums, int numSize, int target) {
+    int i = 0, j = numSize - 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 {
+            return m; // 找到 target ，返回插入点 m
+        }
+    }
+    // 未找到 target ，返回插入点 i
+    return i;
+}
+
+/* 二分查找插入点（存在重复元素） */
+int binarySearchInsertion(int *nums, int numSize, int target) {
+    int i = 0, j = numSize - 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
+        }
+    }
+    // 返回插入点 i
+    return i;
+}
+
+/* Driver Code */
+int main() {
+    // 无重复元素的数组
+    int nums1[] = {1, 3, 6, 8, 12, 15, 23, 26, 31, 35};
+    printf("\n数组 nums = ");
+    printArray(nums1, sizeof(nums1) / sizeof(nums1[0]));
+    // 二分查找插入点
+    int targets1[] = {6, 9};
+    for (int i = 0; i < sizeof(targets1) / sizeof(targets1[0]); i++) {
+        int index = binarySearchInsertionSimple(nums1, sizeof(nums1) / sizeof(nums1[0]), targets1[i]);
+        printf("元素 %d 的插入点的索引为 %d\n", targets1[i], index);
+    }
+
+    // 包含重复元素的数组
+    int nums2[] = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15};
+    printf("\n数组 nums = ");
+    printArray(nums2, sizeof(nums2) / sizeof(nums2[0]));
+    // 二分查找插入点
+    int targets2[] = {2, 6, 20};
+    for (int i = 0; i < sizeof(targets2) / sizeof(int); i++) {
+        int index = binarySearchInsertion(nums2, sizeof(nums2) / sizeof(nums2[0]), targets2[i]);
+        printf("元素 %d 的插入点的索引为 %d\n", targets2[i], index);
+    }
+
+    return 0;
+}