排序 折半，冒泡 快排

/***********************************************
折半插入排序
***********************************************/
#include<stdio.h>
#include<string.h>
#include<math.h>
#include<ctype.h>
#include<stdbool.h>
#include<stdlib.h>
void BinaryInsertSort(int* a, int n)
{
int i, j, k, low, high, m;
for(i = 1; i < n; i++)
{
low = 0;
high = i - 1;
while(low <= high)
{
m = (low + high) / 2;
if(a[m] > a[i]) {
high = m - 1;
}
else {
low = m + 1;
}
}
if(j != i - 1)
{
int temp = a[i];
for(k = i - 1; k >= high + 1; k--) {
a[k + 1] = a[k];
}
a[k + 1] = temp;
}
}
}

void printArray(int* a, int n)
{
for(int i = 0; i < n; i++)
{
printf("%d ", a[i]);
}
printf("\n");
}

int main()
{
int a[7] = {5, 2, 1, 8, 10, 23, 22};
BinaryInsertSort(a, 7);
printArray(a, 7);
return 0;
}

/***********************************

折半查找算法

***********************************/
#include<stdio.h>
#include<string.h>
#include<math.h>
#include<ctype.h>
#include<stdbool.h>
#define COMPARE(x,y) (((x) < (y)) ? -1 : ((x) == (y)) ? 0 : 1)
/* 非递归代码 */
int binsearch(int list[], int searchchnumm, int left, int right)
{
int middle;
while(left <= right) {
middle = (right + left) / 2;
switch(COMPARE(list[middle], searchchnumm)) {
case -1:
left = middle + 1;
break;
case 0:
return middle;
break;
case 1:
right = middle - 1;
break;
default:
break;
}
}
return -1;
}
/* 递归代码 */
int binsearch(int list[], int searchchnumm, int left, int right)
{
int middle;
if(left <= right) {
middle = (left + right) / 2;
switch(COMPARE(list[middle], searchchnumm)) {
case -1:
return binsearch(list, searchchnumm, middle + 1, right);
break;
case 0:
return middle;
break;
case 1:
return binsearch(list, searchchnumm, left, middle - 1);
break;
default:
break;
}
}
return -1;
}
int main()
{
int list[] = {2, 4, 5, 1, -3, 6, 8, 10, 55, 23};
int searchnum = 5;
int length;
length = sizeof(list) / sizeof(int);
printf("%d\n", length);
printf("%d\n", binsearch(list, searchnum, 0, length));
return 0;
}

/***********************************************

冒泡排序

***********************************************/
#include <stdio.h>
void bubbleSort(int arr[], int count)
{
int i = count, j;
int temp;
while(i > 0)
{
for(j = 0; j < i - 1; j++)
{
if(arr[j] > arr[j + 1])
{   temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
i--;
}
}
int main()
{
//测试数据
int arr[] = {5, 4, 1, 3, 6};
//冒泡排序
bubbleSort(arr, 5);
//打印排序结果
int i;
for(i = 0; i < 5; i++) {
printf("%4d", arr[i]);
}
}

/***************************************

快排

***************************************/
#include<stdio.h>
#include<string.h>
#include<math.h>
#include<ctype.h>
#include<stdbool.h>

void swap(int* a, int* b)   //交换两元素的值
{
int t;
t = *a;
*a = *b;
*b = t;
}

void printArray(int a[], int count)   //打印数组元素
{
int i;
for(i = 0; i < count; i++) {
printf("%d ", a[i]);
}
printf("\n");
}

void quick_sort(int a[], int left, int right)
{
int i = left + 1, j = right;
int  key = a[left];
if(left >= right) {
return;
}
/* 从i++和j--两个方向搜索不满足条件的值并交换  *
* 条件为：i++方向小于key，j--方向大于key      */
while(1) {
while(a[j] > key) {
j--;
}
while(a[i] < key && i < j) {
i++;
}
if(i >= j) {
break;
}
swap(&a[i], &a[j]);
if(a[i] == key) {
j--;
}
else {
i++;
}
}
/* 关键数据放到‘中间’ */
swap(&a[left], &a[j]);
if(left  < i - 1) {
quick_sort(a, left, i - 1);
}
if(j + 1 < right) {
quick_sort(a, j + 1 , right);
}
}

int main(void)
{
int a[] = {3, 5, 4, 6, 9, 7, 8, 0, 1};
int n = sizeof(a) / sizeof(*a);
printArray(a, n);
quick_sort(a, 0, n);
printArray(a, n);
return 0;
}