Add Binary search recur in C code (#820)

* Update vector.h

增加功能列表:
获取向量的第 i 个元素
设置向量的第 i 个元素
向量扩容
向量缩容
向量插入元素
向量删除元素
向量交换元素
向量是否为空
向量是否已满
向量是否相等
对向量内部进行排序(升序/降序)
对向量某段数据排序(升序/降序)

* Create hanota.c

* 新增binary_search_recur.c

* Update vector.h

* Delete codes/c/chapter_divide_and_conquer directory

* Update vector.h

* Create binary_search_recur.c

* Create CMakeLists.txt

* Update vector.h

* RollBack vector.h

* Update CMakeLists.txt

* Update binary_search_recur.c

* Update binary_search_recur.c

---------

Co-authored-by: Yudong Jin <krahets@163.com>
This commit is contained in:
王作勋 2023-10-07 21:47:05 +08:00 committed by GitHub
parent 2b59c9ce88
commit ef87bd494a
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2 changed files with 48 additions and 0 deletions

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add_executable(binary_search_recur binary_search_recur.c)
add_executable(hanota hanota.c)

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/**
* File: binary_search_recur.c
* Created Time: 2023-10-01
* Author: Zuoxun (845242523@qq.com)
*/
#include "../utils/common.h"
/* 二分查找:问题 f(i, j) */
int dfs(int nums[], int target, int i, int j) {
// 若区间为空,代表无目标元素,则返回 -1
if (i > j) {
return -1;
}
// 计算中点索引 m
int m = (i + j) / 2;
if (nums[m] < target) {
// 递归子问题 f(m+1, j)
return dfs(nums, target, m + 1, j);
} else if (nums[m] > target) {
// 递归子问题 f(i, m-1)
return dfs(nums, target, i, m - 1);
} else {
// 找到目标元素,返回其索引
return m;
}
}
/* 二分查找 */
int binarySearch(int nums[], int target, int numsSize) {
int n = numsSize;
// 求解问题 f(0, n-1)
return dfs(nums, target, 0, n - 1);
}
/* Driver Code */
int main() {
int target = 6;
int nums[] = {1, 3, 6, 8, 12, 15, 23, 26, 31, 35};
int numsSize = sizeof(nums) / sizeof(nums[0]);
// 二分查找(双闭区间)
int index = binarySearch(nums, target, numsSize);
printf("目标元素 6 的索引 = %d\n", index);
return 0;
}