Re: [問題] 使用亂數產生一組樂透號碼

[Stanauin (希臘行)]

#include <iostream>
#include <ctime>

using namespace std;

class lottery
{
public:
   lottery( unsigned int _all = 49,   // 預設49個數
            unsigned int _pick = 6 ); // 1次抽6個號碼
   virtual ~lottery();

   void setall(unsigned int _all);    // 設置樂透總個數
   void setpick(unsigned int _pick);  // 設置挑選個數
   void draw(unsigned int group = 1); // 抽號碼(group: 抽幾次)

protected:
   void initall();  // 初始化全部樂透號碼
   void shuffle();  // 隨機掉換

private:
   unsigned int all;    // 總個數
   unsigned int pick;   // 抽取數
   int*         number; // 全部的樂透號碼
};

lottery::lottery( unsigned int _all, unsigned int _pick )
{
   all = _all;
   pick = _pick;
   number = NULL;

   initall();
   srand(time(NULL));
}

lottery::~lottery()
{
   if( number )
      delete [] number;
}

void lottery::shuffle()
{
   unsigned i,j,n;
   for( i=0; i<all; ++i )
   {
      n = number[i];
      j = rand()%all;
      number[i] = number[j];
      number[j] = n;
   }
}

void lottery::setall( unsigned int _all )
{
   if( all != _all )
   {
      all = _all;
          initall();
   }
}

void lottery::setpick( unsigned int _pick )
{
   if( pick != _pick )
      pick = _pick;
}

void lottery::initall()
{
   if( number )
      delete [] number;
   number = new int[all];
   for( unsigned int i=0; i<all; ++i )
      number[i] = i+1;
}

void lottery::draw(unsigned int group)
{
   for( unsigned int i=0; i<group; ++i )
   {
      shuffle();
      cout << "group " << i+1 << ": ";
      for( unsigned int j=0; j<pick; ++j )
         cout << number[j] << ' ';
          cout << endl;
   }
}

int main()
{
   // 測試 lottery class: 使用預設值
   lottery lot;
   lot.draw();

   // 測試 set 函式: 100個抽8個，抽5組
   lot.setall( 100 );
   lot.setpick( 8 );
   lot.draw(5);

   return 0;
};

--
賺一下批幣

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→ gyb997:rand()是偽隨機函數，看高德納的計算機設計藝術2
推 gdgy:喔？能不能透露一下，沒聽說過耶