09-排序1 排序 (25分)

#include <iostream>
using namespace std; 

int* copy(int* a,int len)
{
    int* num;
    num = new int[len];
    for ( int i = 0 ; i < len ; i++){
        num[i] = a[i];
    }
    return num;
}

void Buble_Sort(int *a ,int N)
{
    for ( int i = 0 ; i < N - 1 ; i++){
        for ( int j = i + 1 ; j < N ; j++){
            if ( a[i] > a[j]){
                a[i] = a[i] + a[j];
                a[j] = a[i] - a[j];
                a[i] = a[i] - a[j];
            }
        }
    }
}

void Insert_Sort(int *a ,int N)
{
    for ( int i = 1 ; i < N ; i++){
        int tmp = a[i];
        int j;
        for(j = i ; j > 0 && a[j-1] > tmp ; j--){
            a[j] = a[j-1];
        } 
        a[j] = tmp;
    }
}

/* 将N个元素的数组中以A[p]为根的子堆调整为最大堆 */
void PreDown(int *a , int p , int N)
{
    int parent,child;
    int x = a[p];
    for (parent = p ; (parent*2 +1) < N ; parent = child){
        child = 2 * parent+1;
        if ( (child != N-1)&& (a[child] < a[child+1])){
            child++;
        }
        if ( x >= a[child]){
            break;
        }else{
            a[parent] = a[child];
        }
    }
    a[parent] = x;
}

void Heap_Sort(int* a ,int N)
{
    int i;
    for ( i = N/2 - 1 ; i >= 0  ; i--){
        PreDown(a,i,N);
    }

    for ( i = N -1 ; i > 0 ; i--){
        a[0] = a[i] + a[0];
        a[i] = a[0] - a[i];
        a[0] = a[0] - a[i];
        PreDown(a,0,i);
    } 
}

void Merge1(int a[] ,int tmp[],int left ,int right,int rightend)
{
    int leftend = right-1;
    int len = rightend - left + 1;
    int x = left;
    while(left <= leftend && right <= rightend){
        if ( a[left] <= a[right]){
            tmp[x++] = a[left++];
        }else{
            tmp[x++] = a[right++];
        }
    }

    while(left <= leftend){
        tmp[x++] = a[left++];
    }
    while(right <= rightend){
        tmp[x++] = a[right++];
    }

    for( int i = rightend ; len > 0 ; len--,i--){
        a[i] = tmp[i];
    } 
}

void Mergesort(int a[],int tmp[],int left,int right)
{
    if ( left < right){
        int mid = (left+right)/2;
        Mergesort(a,tmp,left,mid);
        Mergesort(a,tmp,mid+1,right);
        Merge1(a,tmp,left,mid+1,right);
    }
}

void Merge_Sort1(int a[] ,int N)
{
    int* tmp;
    tmp = new int[N];
    if (tmp != NULL){
        Mergesort(a,tmp,0,N-1);
    }else{
        cout<<"内存不足"<<endl;
    } 
}

void swap(int* a ,int *b)
{
    int tmp = *a;
    *a = *b;
    *b = tmp;
}

int Median3(int a[],int left,int right)
{
    int center = (left + right) / 2;
    if (a[left] > a[center]) {
        swap(&a[left], &a[center]);
    }
    if (a[left] > a[right]) {
        swap(&a[left], &a[right]);
    }
    if (a[center] > a[right]) {
        swap(&a[center], &a[right]);
    }
    swap(&a[center], &a[right-1]); /* 将基准放在数组右端 */
    return a[right-1];
}

void Qsort(int a[],int left ,int right)
{
    int cutoff = 100;
    int low,high,pivot;
    if ( right - low > cutoff){
        pivot = Median3(a,left,right);
        low = left;
        high = right-1;
        while(1){
            while(a[++low] < pivot);
            while(a[--high] > pivot);
            if ( low < high){
                swap(&a[low],&a[high]);
            }else{
                break;
            }
        }
        swap(&a[low], &a[right - 1]);
        Qsort(a, left, low - 1);
        Qsort(a, low + 1, right);
    }else{
        Insert_Sort(a+left,right-left+1);
    }
}

void Quick_Sort(int a[],int N)
{
    Qsort(a,0,N-1);
 } 

void Print(int *a , int N)
{
    cout<<a[0];
    for ( int i = 1 ; i < N ; i++){
        cout<<" "<<a[i];
    }
}

int main()
{
    int len;
    cin>>len;
    int* a;
    a = new int[len];
    for ( int i = 0 ; i < len ; i++){
        cin>>a[i];
    } 

    //冒泡排序
    int* copy_num; 
    copy_num = copy(a,len);
    Buble_Sort(copy_num,len);
    Print(copy_num,len);
    cout<<endl;

    //插入排序
    copy_num = copy(a,len);
    Insert_Sort(copy_num,len);
    Print(copy_num,len);
    cout<<endl;

    //堆排序
    copy_num = copy(a,len);
    Heap_Sort(copy_num,len);
    Print(copy_num,len);
    cout<<endl;

    //归并排序（递归版） 
    copy_num = copy(a,len);
    Merge_Sort1(copy_num,len);
    Print(copy_num,len);
    cout<<endl;

    /*//快速排序
    copy_num = copy(a,len);
    Quick_Sort(copy_num,len);
    Print(copy_num,len);
    cout<<endl;*/ 

    return 0;
}