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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>
This commit is contained in:
parent
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commit
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8 changed files with 346 additions and 3 deletions
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@ -1,3 +1,5 @@
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add_executable(time_complexity time_complexity.c)
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add_executable(worst_best_time_complexity worst_best_time_complexity.c)
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add_executable(space_complexity space_complexity.c)
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add_executable(iteration iteration.c)
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add_executable(recursion recursion.c)
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82
codes/c/chapter_computational_complexity/iteration.c
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82
codes/c/chapter_computational_complexity/iteration.c
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/**
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* File: iteration.c
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* Created Time: 2023-09-09
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* Author: Gonglja (glj0@outlook.com)
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*/
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#include "../utils/common.h"
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/* for 循环 */
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int forLoop(int n) {
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int res = 0;
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// 循环求和 1, 2, ..., n-1, n
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for (int i = 1; i <= n; ++i) {
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res += i;
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}
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return res;
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}
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/* while 循环 */
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int whileLoop(int n) {
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int res = 0;
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int i = 1; // 初始化条件变量
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// 循环求和 1, 2, ..., n-1, n
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while (i <= n) {
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res += i;
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i++; // 更新条件变量
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}
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return res;
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}
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/* while 循环(两次更新) */
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int whileLoopII(int n) {
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int res = 0;
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int i = 1; // 初始化条件变量
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// 循环求和 1, 4, ...
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while (i <= n) {
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res += i;
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// 更新条件变量
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i++;
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i *= 2;
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}
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return res;
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}
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/* 双层 for 循环 */
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char *nestedForLoop(int n) {
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// 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
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int size = n * n * 26 + 1;
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char *res = malloc(size * sizeof(char));
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// 循环 i = 1, 2, ..., n-1, n
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for (int i = 1; i <= n; ++i) {
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// 循环 j = 1, 2, ..., n-1, n
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for (int j = 1; j <= n; ++j) {
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char tmp[26];
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snprintf(tmp, sizeof(tmp), "(%d, %d), ", i, j);
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strncat(res, tmp, size - strlen(res) - 1);
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}
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}
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return res;
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}
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/* Driver Code */
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int main() {
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int n = 5;
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int res;
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res = forLoop(n);
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printf("\nfor 循环的求和结果 res = %d\n", res);
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res = whileLoop(n);
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printf("\nwhile 循环的求和结果 res = %d\n", res);
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res = whileLoopII(n);
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printf("\nwhile 循环(两次更新)求和结果 res = %d\n", res);
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char *resStr = nestedForLoop(n);
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printf("\n双层 for 循环的遍历结果 %s\r\n", resStr);
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free(resStr);
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return 0;
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}
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55
codes/c/chapter_computational_complexity/recursion.c
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55
codes/c/chapter_computational_complexity/recursion.c
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/**
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* File: recursion.c
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* Created Time: 2023-09-09
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* Author: Gonglja (glj0@outlook.com)
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*/
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#include "../utils/common.h"
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/* 递归 */
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int recur(int n) {
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// 终止条件
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if (n == 1)
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return 1;
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// 递:递归调用
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int res = recur(n - 1);
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// 归:返回结果
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return n + res;
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}
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/* 尾递归 */
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int tailRecur(int n, int res) {
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// 终止条件
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if (n == 0)
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return res;
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// 尾递归调用
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return tailRecur(n - 1, res + n);
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}
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/* 斐波那契数列:递归 */
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int fib(int n) {
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// 终止条件 f(1) = 0, f(2) = 1
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if (n == 1 || n == 2)
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return n - 1;
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// 递归调用 f(n) = f(n-1) + f(n-2)
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int res = fib(n - 1) + fib(n - 2);
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// 返回结果 f(n)
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return res;
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}
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/* Driver Code */
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int main() {
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int n = 5;
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int res;
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res = recur(n);
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printf("\n递归函数的求和结果 res = %d\n", res);
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res = tailRecur(n, 0);
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printf("\n尾递归函数的求和结果 res = %d\n", res);
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res = fib(n);
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printf("\n斐波那契数列的第 %d 项为 %d\n", n, res);
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return 0;
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}
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@ -1,2 +1,3 @@
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add_executable(array_hash_map array_hash_map.c)
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add_executable(simple_hash simple_hash.c)
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68
codes/c/chapter_hashing/simple_hash.c
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68
codes/c/chapter_hashing/simple_hash.c
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/**
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* File: simple_hash.c
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* Created Time: 2023-09-09
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* Author: Gonglja (glj0@outlook.com)
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*/
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#include "../utils/common.h"
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/* 加法哈希 */
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int addHash(char *key) {
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long long hash = 0;
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const int MODULUS = 1000000007;
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for (int i = 0; i < strlen(key); i++) {
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hash = (hash + (unsigned char)key[i]) % MODULUS;
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}
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return (int)hash;
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}
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/* 乘法哈希 */
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int mulHash(char *key) {
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long long hash = 0;
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const int MODULUS = 1000000007;
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for (int i = 0; i < strlen(key); i++) {
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hash = (31 * hash + (unsigned char)key[i]) % MODULUS;
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}
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return (int)hash;
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}
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/* 异或哈希 */
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int xorHash(char *key) {
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int hash = 0;
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const int MODULUS = 1000000007;
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for (int i = 0; i < strlen(key); i++) {
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hash ^= (unsigned char)key[i];
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}
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return hash & MODULUS;
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}
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/* 旋转哈希 */
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int rotHash(char *key) {
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long long hash = 0;
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const int MODULUS = 1000000007;
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for (int i = 0; i < strlen(key); i++) {
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hash = ((hash << 4) ^ (hash >> 28) ^ (unsigned char)key[i]) % MODULUS;
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}
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return (int)hash;
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}
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/* Driver Code */
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int main() {
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char *key = "Hello dsad3241241dsa算123法";
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int hash = addHash(key);
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printf("加法哈希值为 %d\n", hash);
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hash = mulHash(key);
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printf("乘法哈希值为 %d\n", hash);
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hash = xorHash(key);
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printf("异或哈希值为 %d\n", hash);
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hash = rotHash(key);
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printf("旋转哈希值为 %d\n", hash);
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return 0;
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}
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add_executable(binary_search binary_search.c)
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add_executable(two_sum two_sum.c)
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add_executable(binary_search_edge binary_search_edge.c)
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add_executable(hashing_search hashing_search.c)
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add_executable(linear_search linear_search.c)
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add_executable(binary_search_edge binary_search_edge.c)
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add_executable(binary_search_insertion binary_search_insertion.c)
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66
codes/c/chapter_searching/binary_search_edge.c
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66
codes/c/chapter_searching/binary_search_edge.c
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/**
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* File: binary_search_edge.c
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* Created Time: 2023-09-09
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* Author: Gonglja (glj0@outlook.com)
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*/
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#include "../utils/common.h"
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/* 二分查找插入点(存在重复元素) */
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int binarySearchInsertion(int *nums, int numSize, int target) {
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int i = 0, j = numSize - 1; // 初始化双闭区间 [0, n-1]
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while (i <= j) {
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int m = i + (j - i) / 2; // 计算中点索引 m
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if (nums[m] < target) {
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i = m + 1; // target 在区间 [m+1, j] 中
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} else {
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j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
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}
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}
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// 返回插入点 i
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return i;
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}
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/* 二分查找最左一个 target */
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int binarySearchLeftEdge(int *nums, int numSize, int target) {
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// 等价于查找 target 的插入点
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int i = binarySearchInsertion(nums, numSize, target);
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// 未找到 target ,返回 -1
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if (i == numSize || nums[i] != target) {
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return -1;
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}
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// 找到 target ,返回索引 i
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return i;
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}
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/* 二分查找最右一个 target */
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int binarySearchRightEdge(int *nums, int numSize, int target) {
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// 转化为查找最左一个 target + 1
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int i = binarySearchInsertion(nums, numSize, target + 1);
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// j 指向最右一个 target ,i 指向首个大于 target 的元素
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int j = i - 1;
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// 未找到 target ,返回 -1
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if (j == -1 || nums[j] != target) {
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return -1;
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}
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// 找到 target ,返回索引 j
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return j;
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}
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/* Driver Code */
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int main() {
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// 包含重复元素的数组
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int nums[] = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15};
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printf("\n数组 nums = ");
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printArray(nums, sizeof(nums) / sizeof(nums[0]));
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// 二分查找左边界和右边界
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int targets[] = {6, 7};
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for (int i = 0; i < sizeof(targets) / sizeof(targets[0]); i++) {
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int index = binarySearchLeftEdge(nums, sizeof(nums) / sizeof(nums[0]), targets[i]);
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printf("最左一个元素 %d 的索引为 %d\n", targets[i], index);
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index = binarySearchRightEdge(nums, sizeof(nums) / sizeof(nums[0]), targets[i]);
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printf("最右一个元素 %d 的索引为 %d\n", targets[i], index);
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}
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return 0;
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}
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68
codes/c/chapter_searching/binary_search_insertion.c
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68
codes/c/chapter_searching/binary_search_insertion.c
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/**
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* File: binary_search_insertion.c
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* Created Time: 2023-09-09
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* Author: Gonglja (glj0@outlook.com)
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*/
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#include "../utils/common.h"
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/* 二分查找插入点(无重复元素) */
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int binarySearchInsertionSimple(int *nums, int numSize, int target) {
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int i = 0, j = numSize - 1; // 初始化双闭区间 [0, n-1]
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while (i <= j) {
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int m = i + (j - i) / 2; // 计算中点索引 m
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if (nums[m] < target) {
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i = m + 1; // target 在区间 [m+1, j] 中
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} else if (nums[m] > target) {
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j = m - 1; // target 在区间 [i, m-1] 中
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} else {
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return m; // 找到 target ,返回插入点 m
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}
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}
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// 未找到 target ,返回插入点 i
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return i;
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}
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/* 二分查找插入点(存在重复元素) */
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int binarySearchInsertion(int *nums, int numSize, int target) {
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int i = 0, j = numSize - 1; // 初始化双闭区间 [0, n-1]
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while (i <= j) {
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int m = i + (j - i) / 2; // 计算中点索引 m
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if (nums[m] < target) {
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i = m + 1; // target 在区间 [m+1, j] 中
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} else if (nums[m] > target) {
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j = m - 1; // target 在区间 [i, m-1] 中
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} else {
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j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
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}
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}
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// 返回插入点 i
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return i;
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}
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/* Driver Code */
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int main() {
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// 无重复元素的数组
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int nums1[] = {1, 3, 6, 8, 12, 15, 23, 26, 31, 35};
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printf("\n数组 nums = ");
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printArray(nums1, sizeof(nums1) / sizeof(nums1[0]));
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// 二分查找插入点
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int targets1[] = {6, 9};
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for (int i = 0; i < sizeof(targets1) / sizeof(targets1[0]); i++) {
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int index = binarySearchInsertionSimple(nums1, sizeof(nums1) / sizeof(nums1[0]), targets1[i]);
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printf("元素 %d 的插入点的索引为 %d\n", targets1[i], index);
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}
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// 包含重复元素的数组
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int nums2[] = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15};
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printf("\n数组 nums = ");
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printArray(nums2, sizeof(nums2) / sizeof(nums2[0]));
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// 二分查找插入点
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int targets2[] = {2, 6, 20};
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for (int i = 0; i < sizeof(targets2) / sizeof(int); i++) {
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int index = binarySearchInsertion(nums2, sizeof(nums2) / sizeof(nums2[0]), targets2[i]);
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printf("元素 %d 的插入点的索引为 %d\n", targets2[i], index);
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}
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return 0;
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}
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