间隙插入排序实现

Question

我试图在c++中实现间隔插入排序，称为库排序。我理解这个概念，但是我很难把它从常规的插入排序中取出来。我不知道该如何解释数组中的间隔。我一直使用整数0来指定间隙。到目前为止，我的代码如下，这是一个工作插入排序修改位。如何实现库排序?我在google上查了20页，却没有看到任何一种编程语言的实际代码示例。

#include <iostream>
#include <stdlib.h>
#include <time.h>
#include <vector>
using namespace std;
vector<int> librarySort(int arr[20])
{
int j,tmp;
vector<int> array;
for (int i=0;i<20;i++)
{
    array.push_back(0);
    array.push_back(arr[i]);
}
for (int i=0;i<40;i++) { cout << array[i] << ",";}
cout << endl;
for (int i = 1; i < 40; i++) 
{
    j = i;
    while (j > 0 && array[j - 1] > array[j]) 
    {
        tmp = array[j];
        array[j] = array[j - 1];
        array[j - 1] = tmp;
        j--;
    }
}
for (int i=0;i<40;i++) { cout << array[i] << ",";}
return array;
}
int main()
{
srand(time(0));
int array[20]= {0};
for (int i=0;i<20;i++)
{
    int n=rand()%19+1;
    tmp=array[i];
    array[i]=array[n];
    array[n]=tmp;
}
for (int i=0;i<20;i++) { cout << array[i] << ",";}
cout << endl;
librarySort(array);
}

Answer 1

这里有一个完整的描述和实现。缺口被定义为您不会使用的任何值。如果使用指针，NULL是一个不错的选择。
在一般情况下，您必须为包含原始数据的数组创建一个辅助数组。在本例中:

#define MAX 20
#define MAX2 100//The size of the gapped array must be bigger
#define EMPTY -1//Use this constant instead of zeros.
bool isEmpty(int index, int gappedArray[MAX2]) {
    return gappedArray[index]>=0;
}
vector<int> libSort(int arr[MAX]) {
    int aux[MAX];
    for(int i=0;i<MAX;i++) aux = i;
    //Add your library sort algorithm here
    //However instead of comparing arr[i] with arr[j], compare arr[aux[i]] with arr[aux[j]]
    //Then, when you are going to insert sorted values, insert aux[pos], not arr[pos]
}

这里有一个库排序伪代码:

Rebalance(Array S, Integer iniLen, Integer finLen)
k = finLen-1
step = finLen/iniLen
for j=iniLen-1 to 0:
    S[k] = S[j]
    S[j] = NONE
    k = k-step
end for
LibrarySort(Array A, Integer n, Float epsilon, Array S)
    goal = 1
    pos = 0
    sLen = (Integer)(1+epsilon)*n
    while pos<n://For each round do this:
        for i=1 to goal://Insert 'goal' elements to the sorted array S
            //Search a position to insert A[pos]
            insPos = binarySearch(A[pos], S, sLen)
            if not IS_EMPTY(S[insPos]):
                //Move elements to the right or the left in order to free
                //insPos
                freeSpace(insPos, S, sLen)
            end if
            S[insPos] = A[pos]//Insert new element
            pos = pos + 1
            if pos>n://All elements have been inserted
                return LibrarySort
            end if
        end for
        prevLen = sLen
        sLen = min( (2+2*epsilon)*goal, (1+epsilon)*n )
        //Rebalance array S
        Rebalance(S, prevLen, sLen)
        goal = goal * 2
    end while