文件和数组的排序

#include <iostream>
#include <fstream>
#include <vector>
#include <assert.h>
using namespace std;
template <class T>
void order(vector <T>  &a)
{
    int count = a.size();
    T temp;
    for (int i=0;i<count;i++)
    {
        for (int j=0;j<count-i-1;j++)
        {
            if (a[j]>a[j+1])
            {
                temp = a[j];
                a[j] = a[j+1];
                a[j+1] = temp;
            }
        }
    }
}
template <class T>
void order(T arr[],int len) 
{
    T  temp;
    for (int i = 0; i < len - 1; i++)
        for (int j = 0; j < len - 1 - i; j++)
            if (arr[j] > arr[j + 1]) 
            {
                temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
}
int main(void)
{
    //文件排序
    ifstream fin("order.txt");
    assert(fin);
    vector<double> a;    double temp;
    while(!fin.eof())
    {
        fin>>temp;
        a.push_back(temp);
    }
    fin.close();
    order(a);
    ofstream fout("order_out.txt");
    assert(fout);
    for (int i = 0; i<a.size(); i++)
    {
        fout<<a[i]<<endl;
    }
    //数组排序
    double arr[] = { 22, 34, 3,289754282,12313,1231424214};
    int len = (int) sizeof(arr) / sizeof(*arr);
    order(arr,len);
}

 快速排序法（速度最快）

#include<iostream>
using namespace std;

void quickSort(int s[], int l, int r)
{
    if (l< r)
    {    
        int i = l, j = r, x = s[l];
        while (i < j)
        {    while(i < j && s[j]>= x)     j--; 
        if(i < j)    s[i++] = s[j];
        while(i < j && s[i]< x) i++; 
        if(i < j)     s[j--] = s[i];
        }
        s[i] = x;
        quickSort(s, l, i - 1); 
        quickSort(s, i + 1, r);
    }
}
int main()
{
    int array[]={4,5,12,4,6,5,7,1,3,7};
    int len=sizeof(array)/sizeof(int);
    quickSort(array,0,len-1);
    system("pause");
    return 0;
}