*** 把一个文件中的整数排序后输出到另一个文件中

 

#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

template<class T>
bool decreOrder(T &a, T &b)
{
    return (a < b);
}
template<class T>
bool increOrder(T &a, T &b)
{
    return (a > b);
}

template<class T>
void Sort(vector<T> & v, bool (*compare)(T &,T &))
{
    int len = v.size();
    for (int i = 0; i < len-1; i++)
    {
        for (int j = len-1; j > i; j--)
        {
            if (compare(v[j-1],v[j]))
            {
                T temp;
                temp = v[j];
                v[j] = v[j-1];
                v[j-1] = temp;
            }
        }
    }
}

int main()
{
    vector<int> v;
    ifstream in("c:\\data.txt");
    if (!in)
    {
        cout << "Failed to open data.txt!" << endl;
        return 1;
    }

    while (!in.eof())
    {
        int temp;
        in >> temp;
        v.push_back(temp);
    }
    in.close();

    // sort the vector
    Sort<int>(v, increOrder<int>);

    // output the numbers in vector into file output.txt
    ofstream out("c:\\output.txt");
    if (!out)
    {
        cout << "Failed to open output.txt!" << endl;
        return 1;
    }

    for (int i = 0; i < v.size(); i++)
    {
        out << v[i] << endl;
    }

    out.close();
    cout << "End of the program" << endl;
    return 0;
}