//MySort.h
#include <stdlib.h>
#ifndef MYSORT_H_INCLUDED
#define MYSORT_H_INCLUDED
/*函数声明 设置默认参数*/
template <class T>
int QuickSort_ChooseBaseNumber_First(T a[], int left, int right);
template <class T>
int QuickSort_ChooseBaseNumber_Middle(T a[], int left, int right);
template <class T>
int QuickSort_ChooseBaseNumber_Rand(T a[], int left, int right);
template <class T>
int QuickSort_ChooseBaseNumber_Ballance(T a[], int left, int right);
template <class T>
bool cmp_default(T& a, T& b);//默认比较函数,规定其返回值使得排序从小到大
template <class T>
void InsertionSort(T a[], int size,bool (*cmp)(T&, T&) = cmp_default);
template <class T>
void QuickSort(T a[], int left, int right, bool (*cmp)(T&, T&) = cmp_default, int (*getbase)(T[], int, int) = QuickSort_ChooseBaseNumber_Middle);
/*函数声明 设置默认参数*/
template <class T>
bool cmp_default(T& a, T& b)//默认比较函数,规定其返回值使得排序从小到大
{
return a < b;//若为结构体或类对象,需要重载运算符或者比较直接用其成员
}
template <class T>
void InsertionSort(T a[], int size,bool (*cmp)(T&, T&))//二分插入排序,cmp为比较函数指针,默认为cmp_default从小到大
{
T temp;
int left, right, mid;
for(int i = 0; i < size; ++i)
{
temp = a[i];
left = 0;
right = i - 1;
while(left <= right)
{
mid = (left + right) >> 1;
if( cmp(temp, a[mid]) )
right = mid - 1;
else left = mid + 1;
}
for(int j = i - 1; j >= left; --j)
a[j + 1] = a[j];
a[left] = temp;
}
}
/*下面快速排序*/
/*快排,找个基准数,把集合分成两块,左边全部比基准数小,右边全部大*/
template <class T>
void QuickSort(T a[], int left, int right, bool (*cmp)(T&, T&), int (*getbase)(T[], int, int))
{
if(left >= right) return;
int l = left, r = right;
/*选取基准数开始*/
int base_index = getbase(a, left, right);
swap(a[left], a[base_index]);//和第一个交换
T base = a[l];
/*选取基准数结束*/
while(l < r)//开始以基准数为中进行左右分堆
{
while(!cmp(a[r], base) && l < r) --r;
if(l < r) a[l++] = a[r];
while(cmp(a[l], base) && l < r) ++l;
if(l < r) a[r--] = a[l];
}
a[l] = base;
int pos = l;
QuickSort(a, left, pos - 1, cmp);//递归左边
QuickSort(a, pos + 1, right, cmp);//递归右边
}
/*下面为选取基准数的几种方法*/
template <class T>
int QuickSort_ChooseBaseNumber_First(T a[], int left, int right)//选取基准数
{
return left; /*选取第一个数*/
}
template <class T>
int QuickSort_ChooseBaseNumber_Middle(T a[], int left, int right)//选取基准数
{
return (left + right) / 2; /*选取中间*/
}
template <class T>
int QuickSort_ChooseBaseNumber_Rand(T a[], int left, int right)//选取基准数
{
return (rand() % (right - left) + left); /*选取随机数作为基准*/
//使用时尽量在最外调用处初始随机数种子
//不能在这里初始,因为调用时间间隔太小
}
template <class T>
int QuickSort_ChooseBaseNumber_Ballance(T a[], int left, int right)//选取基准数
{
/*平衡快排选取*/
if(right - left < 3) return left;//如果不足3个返回第一个
int mid = (left + right) / 2;
if(a[left] > a[mid]) swap(a[left], a[mid]);
if(a[mid] > a[right]) swap(a[mid], a[right]);
if(a[left] > a[mid]) swap(a[left], a[mid]);
return mid;
}
#endif // MYSORT_H_INCLUDED
//main.cpp
#include <iostream>
#include <string>
#include <cstdlib>
#include <conio.h>
#include "MySort.h"
using namespace std;
int menu();//菜单
int input(string* str);
void output(string* str, int n);
void s1(string *str);//二分插入排序
void s2(string *str);//快速排序
bool cmpcmp(string &a,string &b) //从大到小的比较函数
{
return a > b;
}
int main()
{
system("color 0A");
string str[10000];
while(1)
{
system("cls");
int n = menu();
while(n < 1 || n > 3)
{
system("cls");
cout << "输入错误,请重新输入!" << endl;
n = menu();
}
switch(n)
{
case 1:s1(str);break;
case 2:s2(str);break;
case 3:exit(0);break;
default:break;
}
}
return 0;
}
int input(string* str)
{
int n;
cout << "请输出测试数据量n :" << endl;
cin >> n;
cout << "请输入" << n << "个字符串,空格或换行隔开:" << endl;
for(int i = 0; i < n; ++i) cin >> str[i];
return n;
}
void output(string* str, int n)
{
for(int i = 0; i < n; ++i) cout << str[i] << ' ';
cout << endl;
}
int menu()//菜单
{
cout << "\t\t*******************************************" << endl
<< "\t\t* *" << endl
<< "\t\t* 1.插入排序 *" << endl
<< "\t\t* 2.快速排序 *" << endl
<< "\t\t* 3.退出 *" << endl
<< "\t\t* *" << endl
<< "\t\t* 请按数字键进行选择 *" << endl
<< "\t\t*******************************************" << endl;
char ch = getch();
return (int)ch - '0';
}
void s1(string *str)//二分插入排序
{
system("cls");
cout << "\t\t二分插入排序\t\t" << endl;
int n = input(str);
cout << "从小到大排序好后:" <<endl;
InsertionSort(str, n);
output(str, n);
cout <<"再从大到小排:" << endl;
InsertionSort(str, n, cmpcmp);
output(str, n);
system("pause");
}
void s2(string *str)//快速排序
{
system("cls");
cout << "\t\t快速排序\t\t" << endl;
int n = input(str);
cout << "从小到大排序好后:" <<endl;
QuickSort(str, 0 , n - 1);
output(str, n);
cout <<"再从大到小排:" << endl;
QuickSort(str, 0 , n - 1, cmpcmp,QuickSort_ChooseBaseNumber_Ballance);
output(str, n);
system("pause");
}
上学期数据结构的一个作业。