一个可以返回受限集中随机数字的类，返回值不重复。

#include <vector>
using namespace std;

class RandomLimitNum
{
public: 
    RandomLimitNum(int begin_num,int end_num);
    bool GetCurrentRandomNum(int * result);
private:
    vector<int> m_vector;
};

#include "stdafx.h"
#include "RandomLimitNum.h"

RandomLimitNum::RandomLimitNum(int begin_num,int end_num)
{
    for (int i = begin_num;i <= end_num; ++i)
    {
        m_vector.push_back(i);
    }
}
bool RandomLimitNum::GetCurrentRandomNum(int * result)
{
    size_t count = m_vector.size();
    if (count == 0)
    {
        return false;
    }
    else if (count == 1)
    {
        *result = m_vector[0];
        m_vector.erase(m_vector.begin());
        return true;
    }
    SYSTEMTIME st;
    GetLocalTime(&st);
    srand(st.wSecond*st.wMinute+st.wSecond);
    int random = rand()%count;
    *result = m_vector[random];
    vector<int>::iterator delete_it = m_vector.begin()+random;
    m_vector.erase(delete_it);
    return true;
}