循环排序
循环排序是一种就地排序算法。它也是基于比较的排序，对于任何其他就地排序技术而言都是有效的。它找到执行排序任务所需的最小内存写入数。
循环排序技术的复杂性
时间复杂度：O（n^2）
空间复杂度：O(1)
输入输出
Input: A list of unsorted data: 23 63 98 74 20 14 36 45 99 78 Output: Array before Sorting: 23 63 98 74 20 14 36 45 99 78 Array after Sorting: 14 20 23 36 45 63 74 78 98 99
算法
cycleSort(array, size)
输入-数据数组，以及数组中的总数
输出- 排序的数组
Begin
for start := 0 to n – 2 do
key := array[start]
location := start
for i := start + 1 to n-1 do
if array[i] < key then
location:=location +1
done
if location = start then
ignore lower part, go for next iteration
while key = array[location] do
location := location +1
done
if location ≠ start then
swap array[location] with key
while location ≠ start do
location := start
for i := start + 1 to n-1 do
if array[i] < key then
location:=location +1
done
while key = array[location]
location := location +1
if key ≠ array[location]
swap array[location] and key
done
done
End示例
#include<iostream>
using namespace std;
void swapping(int &a, int &b) { //swap the content of a and b
int temp;
temp = a;
a = b;
b = temp;
}
void display(int *array, int size) {
for(int i = 0; i<size; i++)
cout << array[i] << " ";
cout << endl;
}
void cycleSort(int *array, int n) {
for(int start = 0; start<n-1; start++) { //put array element in the correct place
int key = array[start];
int location = start;
for(int i = start+1; i<n; i++) { //count smaller element in the right side of key
if(array[i] < key)
location++;
}
if(location == start) //when it is in correct place go for next iteration
continue;
while(key == array[location]) //if same data is found increase location
location++;
if(location != start)
swapping(array[location], key);
while(location != start) {
location = start;
for(int i = start+1; i<n; i++) { //location to put element
if(array[i] < key)
location++;
}
while(key == array[location]) //if same data is found increase location
location++;
if(key != array[location])
swapping(key, array[location]);
}
}
}
int main() {
int n;
cout << "Enter the number of elements: ";
cin >> n;
int arr[n]; //create an array with given number of elements
cout << "输入元素：" << endl;
for(int i = 0; i<n; i++) {
cin >> arr[i];
}
cout << "Array before Sorting: ";
display(arr, n);
cycleSort(arr, n);
cout << "Array after Sorting: ";
display(arr, n);
}输出结果
Enter the number of elements: 10 输入元素： 23 63 98 74 20 14 36 45 99 78 Array before Sorting: 23 63 98 74 20 14 36 45 99 78 Array after Sorting: 14 20 23 36 45 63 74 78 98 99