c++实现希尔排序

#include<stdio.h>
#include<iostream>
using namespace std;

#define LIST_INIT_SIZE 100
#define LISTINCREMENT 10
#define ElemType int

typedef struct{
	ElemType *elem;
	int length;
	int listsize;
}SqList;

//建顺序表
void InitList_Sq(SqList &L)
{
	L.elem = (ElemType *)malloc(LIST_INIT_SIZE*sizeof(ElemType));
	if (!L.elem) cout << "存储分配失败!" << endl;
	L.length = 0;
	L.listsize = LIST_INIT_SIZE;
}

//在第i位置插入元素e
void ListInsert_Sq(SqList &L, int i, ElemType e)
{
	int *newbase;
	if (i<1 || i>L.length + 1) cout << "位置错误!" << endl;
	if (L.length >= L.listsize)
	{
		newbase = (ElemType *)realloc(L.elem, (L.listsize + LISTINCREMENT)*sizeof(ElemType));
		if (!newbase) cout << "重新分配地址错误!" << endl;
		L.elem = newbase;
		L.listsize += LISTINCREMENT;
	}
	int *p, *q;
	q = &(L.elem[i - 1]);
	for (p = &(L.elem[L.length - 1]); p >= q; --p)	//将第i位置及其以后的元素后移一个位置
		*(p + 1) = *p;
	*q = e;
	++L.length;
}

//希尔排序
void ShellInsert(SqList &L, int dk)
{
	int i=0, j=0;
	int	t;	//可以理解为临时变量
	for (i = dk ; i < L.length;++i)		//以加dk后的元素为循环变量，逐个与为加dk的元素比较
	if (L.elem[i] < L.elem[i - dk])
	{
		t = L.elem[i];
		for (j = i - dk; j>=0 && t < L.elem[j]; j -= dk)	//若元素小于相邻dk距离的元素，则元素前移dk
			L.elem[j + dk] = L.elem[j];
		L.elem[j + dk] = t;		//插入元素
	}
}


//打印
void PrintL(SqList &L)
{
	int i = 0;
	while (i < L.length)
	{
		cout << L.elem[i] << " ";
		i++;
	}
	cout << endl;
}

void main()
{
	SqList L;
	int dk;

	//创建顺序表L并插入数据
	InitList_Sq(L);
	ListInsert_Sq(L, 1, 56);	ListInsert_Sq(L, 2, 25);
	ListInsert_Sq(L, 3, 98);	ListInsert_Sq(L, 4, 12);
	ListInsert_Sq(L, 5, 78);	ListInsert_Sq(L, 6, 88);
	ListInsert_Sq(L, 7, 39);	ListInsert_Sq(L, 8, 95);
	ListInsert_Sq(L, 9, 91);	ListInsert_Sq(L, 10, 86);
	ListInsert_Sq(L, 11, 80);	ListInsert_Sq(L, 12, 99);
	cout << "La的元素为：";
	PrintL(L);
	
	//dk为3时，输出每一趟的结果
	for (dk = 3; dk > 0; --dk)
	{
		ShellInsert(L, dk);
		cout << "dk=" << dk << "第" << 3 - dk + 1 << "趟结果为：";
		PrintL(L);
	}
	
	//防止运行结果一闪而过
	system("pause");
}