经典排序算法总结（代码）
经典排序算法总结（代码）
·冒泡法
·快速排序
·插入排序
·希尔（shell）排序
·选择排序
·堆排序
·归并排序
附：
排序算法原理：http://zh.wikipedia.org/wiki/Category:%E6%8E%92%E5%BA%8F%E7%AE%97%E6%B3%95
flash演示:http://www.tyut.edu.cn/kecheng1/site01/suanfayanshi/list.asp?id=7
归并排序的具体介绍在下面的文章里：
递归算法学习---归并排序
#include <iostream>
#include <string>
using namespace std;
/* 冒泡法
左右元素相比，往后冒泡
*/
template<typename T>
void BubbleSort(T* r, int n)
{
T temp;
int i,j;
for (i=0;i<n-1;i++)
{
for (j=0;j<n-i-1;j++)
{
if (r[j] > r[j+1])
{
temp = r[j];
r[j] = r[j+1];
r[j+1] = temp;
}
}
}
}
/*快速排序
左边比他小，右边比他大，每次得到一个最左边数据的位置*/
template<typename T>
void QuickSort(T a[],int low,int high)
{
if(low < high)
{
T elem = a[low];
int l = low, r = high;
while(l < r)
{
while(l < r && a[r] >= elem) r--;
if (l < r)
{
a[l++] = a[r];
}
while(l< r && a[l] <= elem) l++;
if (l < r)
{
a[r--] = a[l];
}
}
a[r] = elem;
QuickSort(a,low,r-1);
QuickSort(a,r+1,high);
}
}
/*插入排序
向右移，a[j+1]=a[j]*/
template<typename T>
void insert_sort(T a[],int n)
{
int i,j;
T elem;
for (i= 1;i<n ;++i)
{
j = i- 1;
elem = a[i];
while(j>=0&& elem < a[j] )
{
a[j+1] = a[j]; j--;
}
a[j+1] = elem;
}
}
/*希尔（shell）排序
把插入排序的改成d即可*/
template<typename T>
void shell_insert(T array[],int d,int len)
{
int i,j;
T elem;
for ( i = d;i < len;i++)
{
j = i - d;
elem = array[i];
while (j >= 0&& elem < array[j])
{
array[j+d] = array[j];
j = j - d;
}
array[j+d] = elem;
}
}
template<typename T>
void shell_sort(T array[],int len)
{
int inc = len;
do
{
inc = inc/2;
shell_insert(array,inc,len);
}
while (inc >1);
}
/*选择排序
逐一比较，最小的放前面*/
template <typename T>
void SelectSort(T a[],int n)
{
int i,j,elemNum;
T elem;
for (i=0;i<n-1;i++)
{
elemNum = i;
for (j= i+1;j<n;j++)
{
if (a[j] < a[elemNum])
{
elemNum = j;
}
}
if (elemNum != i)
{
elem = a[i];
a[i] = a[elemNum];
a[elemNum] = elem;
}
}
}
/*堆排序
a[s]>=a[2*s] &&a[s]>=a[2*s+1]*/
template<typename T>
void Max_heap(T a[],int S,int len)
{
int l = 2*S;
int r = 2*S+1;
int maxI = S;
T elem;
if (l < len && a[l] > a[maxI])
{
maxI = l;
}
if (r < len && a[r] > a[maxI])
{
maxI = r;
}
if (maxI != S)
{
elem = a[S];
a[S] = a[maxI];
a[maxI] = elem;
Max_heap(a,maxI,len);
}
}
template<typename T>
void HeapSort(T a[],int n)
{
int i;
T elem;
for (i = n/2;i>=0;i--)
{
Max_heap(a,i,n);
}
for (i= n-1;i>=1;i--)
{
elem = a[0];
a[0] = a[i];
a[i] = elem;
n = n-1;
Max_heap(a,0,n);
}
}
/*归并排序
左边小左边，左边++；右边小取右边，右边++*/
template<typename T>
void merge(T array[], int low, int mid, int high)
{
int k;
T *temp = new T[high-low+1]; //申请空间，使其大小为两个已经排序序列之和，该空间用来存放合并后的序列
int begin1 = low;
int end1 = mid;
int begin2 = mid + 1;
int end2 = high;
for (k = 0; begin1 <= end1&& begin2 <= end2; ++k) //比较两个指针所指向的元素，选择相对小的元素放入到合并空间，并移动指针到下一位置
{
if(array[begin1]<=array[begin2])
temp[k] = array[begin1++];
else
temp[k] = array[begin2++];
}
if(begin1 <= end1) //若第一个序列有剩余，直接拷贝出来粘到合并序列尾
memcpy(temp+k, array+begin1, (end1-begin1+1)*sizeof(T));
if(begin2 <= end2) //若第二个序列有剩余，直接拷贝出来粘到合并序列尾
memcpy(temp+k, array+begin2, (end2-begin2+1)*sizeof(T));
memcpy(array+low, temp, (high-low+1)*sizeof(T));//将排序好的序列拷贝回数组中
delete temp;
}
template<typename T>
void merge_sort(T array[], unsigned int first, unsigned int last)
{
int mid = 0;
if(first<last)
{
//mid = (first+last)/2; /*注意防止溢出*/
mid = first/2 +last/2;
//mid = (first & last) + ((first ^ last) >> 1);
merge_sort(array, first, mid);
merge_sort(array, mid+1,last);
merge(array,first,mid,last);
}
}
template<typename T>
void Print(T* r,int n)
{
for (int i=0;i<n;i++)
{
cout << r[i] << endl;
}
}
int main()
{
cout << "Welcome..."<< endl;
double r[] ={1.5,3.2,5,6,9.2,7,2,4,8};
//BubbleSort(r,9);
QuickSort(r,0,8);
//insert_sort(r,9);
//shell_sort(r,9);
//SelectSort(r,9);
//HeapSort(r,9);
// merge_sort(r,0,8);
Print(r,9);
return 0;
}