排序（模板）

快速排序：

#include <cstring>
#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;

int a[100005];

void Sort(int left, int right)
{
    if ( left >= right )
        return ;
    int i = left, j = right;
    int key = a[left];
    while ( i < j )
    {
        while ( i < j&&key <= a[j] )
            j--;
        a[i] = a[j];
        while ( i < j&&key >= a[i] )
            i++;
        a[j] = a[i];
    }
    a[i] = key;
    Sort(left, i-1);
    Sort(i+1, right);
}

int main()
{
    int n, i;
    while ( ~scanf ( "%d", &n ) )
    {
        for ( i = 0;i < n; i++ )
            scanf ( "%d", &a[i] );
        Sort(0, n-1);
        for ( i = 0;i < n; i++ )
            printf ( i != n-1 ? "%d " : "%d\n", a[i] );
    }
}

堆排序：

#include <cstring>
#include <cstdio>
#include <algorithm>
#include <iostream>
using namespace std;

void heapAdjust ( int a[], int i, int size )
{
    int left_size = 2*i;
    int right_size = 2*i+1;
    int cnt = i;
    
    /*The rules of large Root Sort   大根堆的規則*/
    if ( i <= size/2 )
    {
        if ( left_size <= size && a[left_size] > a[cnt] )
            cnt = left_size;
        if ( right_size <= size && a[right_size] > a[cnt] )
            cnt = right_size;
            
        /*Overall adjustment Sort   對序列的整體調整*/
        if ( cnt != i )
        {
            swap( a[i], a[cnt] );
            heapAdjust ( a, cnt, size );
        }
    }
}

void buildHeap ( int a[], int size )
{
    int i;
    for ( i = size/2;i > 0; i-- )
    {
        heapAdjust ( a, i, size );
    }
}

void heapSort( int a[], int size )
{
    int i;

    /*To establish a large Root Sort under the initial state
                                                          建立初始狀態下的大根堆*/
    buildHeap ( a, size );

    /*Adjust the Sort          調整序列*/
    for ( i = size;i > 0; i-- )
    {
        swap ( a[1], a[i] );
        heapAdjust ( a, 1, i-1 );
    }
}

int main()
{
    int size, i;
    int a[100];

    /*輸入數據     Input data*/
    scanf ( "%d", &size );
    for ( i = 1;i <= size; i++ )
    {
        scanf ( "%d", &a[i] );
    }

    /*堆排序      Heap sort start*/
    heapSort( a, size );

    /*輸出數據     Output data*/
    for ( i = 1;i <= size; i++ )
    {
        printf ( i == size ? "%d\n" : "%d ", a[i] );
    }
    return 0;
}

希爾排序

#include <cstring>
#include <cstdio>
#include <algorithm>
#include <iostream>
using namespace std;

int a[10002], n;

void Shell(int p, int r)
{
    int d = r-p+1;       //將 length(A) 賦給d 
    int i, j, tmp;
    while ( d >= 1 )
    {
        d = d/2;
        for ( i = p+d;i <= r; i++ )
        {
            tmp = a[i];
            j = i-d;         //從i的前一個步長開始
            while ( j >= p&&tmp < a[j] )
            {
                a[j+d] = a[j];//記錄後移 
                j = j-d;      //向前計數 
            }
            a[j+d] = tmp;
        }
    }
}

int main()
{
    int i;
    while ( ~scanf ( "%d", &n ) )
    {
        for ( i = 1;i <= n; i++ )
            scanf ( "%d", &a[i] );
        Shell(1, n);
        for ( i = 1;i <= n; i++ )
            printf ( "%d ", a[i] );
    }
}

歸併排序

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

int s[100005];

void comput( int s[], int top, int mid, int en )
{
    int left_size = mid - top +1;
    int right_size = en - mid;
    int LEFT[left_size+1];
    int RIGHT[right_size+1];
    for( int i = 0;i < left_size; i++ )
    {
        LEFT[i] = s[top+i];
    }
    LEFT[left_size] = ( 1<<30 ); //這裏我稍微註釋一下，這裏主要是爲了不用後面的while（），相信在很多的模板中都會出現while()，這是因爲可能會在數組裏殘留這一些                                                      元素，而這種方法完全的避免了while，因爲他們數組的最後一個都是很大很大的數當然會排在最後了，之要輸出個數保持好就可以避免了，哈哈  
    for( int i = 0;i < right_size; i++ )
    {
        RIGHT[i] = s[mid+i+1];
    }
    RIGHT[right_size] = ( 1<<30 );
    int i = 0;
    int j = 0;
    for ( int k = top; k <= en; k++)
    {
        if( LEFT[i] <= RIGHT[j] )
        {
            s[k] = LEFT[i++];
        }
        else
        {
            s[k] = RIGHT[j++];
        }
    }
    return ;
}

void mergesort( int s[], int top, int en )
{
    if( top != en )
    {
        int mid = ( top + en ) / 2;
        mergesort( s, top, mid );
        mergesort( s, mid+1, en );
        comput( s, top, mid, en );
    }
    return ;
}

int main()
{
    int n,i;
    while ( ~scanf ( "%d", &n ) && n != 0 )
    {
        for( i = 0;i < n; i++ )
        {
            scanf ( "%d", &s[i] );
        }
        mergesort( s, 0, n-1 );
        for( i = 0;i < n; i++ )
        {
            printf( "%d ", s[i] );
        }
    }
}