C++：插入排序

一、直接插入排序

直接插入排序

#include <bits/stdc++.h>
using namespace std;

template<class T>
void DirectInsort(T * a, int n)
{
    int i;
    for (i = 1; i < n; i++)
    {
        T temp = a[i];
        for (int j = i - 1; j >= 0; j--)
        {
            if (temp < a[j])
            {
                a[j + 1] = a[j]; 
            }
            else
            {
                a[j + 1] = temp;
                break;
            }
        }
    }
}

int main()
{
    int len;
    cin >> len;
    int * a = new int[len];
    for (int i = 0; i < len; i++)
    {
        cin >> a[i];
    }
    DirectInsort(a, len);
    
    for (int i = 0; i < len; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;
    delete a;
    return 0;
}

/*
测试
5
1 3 2 6 10
*/

二、折半插入排序

折半插入排序

#include <iostream>
using namespace std;

template<class T>
void BinInsort(T * a, int n)
{
    int i, k, r;
    for (i = 1; i < n; i++)
    {
        T temp = a[i];
        while(k <= r) // 计算插入位置k
        {
            int m = (k + r) / 2;
            if (temp < a[m])
            {
                r = m - 1;
            }
            else
            {
                k = m + 1;
            }
        }
        for (r = i; r > k; r--)    // 移动a[k..i-1]至a[k+1..i]
        {
            a[r] = a[r - 1];
        }
        a[k] = temp; //完成插入
    }
}

int main()
{
    int len;
    cin >> len;
    int * a = new int[len];
    for (int i = 0; i < len; i++)
    {
        cin >> a[i];
    }
    BinInsort(a, len);
    
    for (int i = 0; i < len; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;
    delete a;
    return 0;
}

/*
测试
5
1 3 2 6 10
*/

三、Shell排序

Shell排序

#include<bits/stdc++.h>
using namespace std;

template<class T>
void ShellInsort(T A[], int n, int s) // n为数组大小，s为分组间隔
{
    int i, j, k;
    T temp;
    for (k = s; k > 0; k >>= 1) // 分组次数
    {
        for (i = k; i < n; i++)
        {
            // 对A[i]所在组前面部分插入排序
            temp = A[i];
            j = i - k;
            while (j >= 0 && temp < A[j])
            {
                // 前面元素已经有序，第2个条件避免无效比较
                A[j + k] = A[j];
                j -= k;
                A[j + k] = temp;
            }
        }
    }
}

int main()
{
    int len;
    cin >> len;
    int * a = new int[len];
    for (int i = 0; i < len; i++)
    {
        cin >> a[i];
    }
    ShellInsort(a, len);
    
    for (int i = 0; i < len; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;
    delete a;
    return 0;
}

/*
测试
10
2 8 6 7 5 4 3 1 0 9
*/