《数据结构与算法之6 扑克牌洗牌算法》

【1】扑克牌洗牌算法：
*********************************************
函数名：void get_rand_number(int array[],int length)

功能：随机交换数组中位置，达到洗牌目的

备注：全局洗牌：value = rand()%length;    局部洗牌：value = index+rand()%length;
    注意：rand()函数可取0~375555.

*********************************************
#include <iostream>

using namespace std;

void get_rand_number(int array[],int length);
void main()
{
    int array [] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,45,46,47,
48,49,50,51,52};
    int length = sizeof(array)/sizeof(int);

    get_rand_number(array,length);
    for (int i = 0;i<length;i++)
    {
        cout<<array[i]<<"  ";
        if (i>0&&i%12==0)
        {
            cout<<endl;
        }
    }
}

void get_rand_number(int array[],int length)
{
    int index;
    int value;
    int median;

    if (NULL==array||0==length)
    {
        return;
    }
    
    for (index=0;index<length;index++)
    {
        value = rand()%length;

        median = array[index];
        array[index] = array[value];
        array[value] = median;
    }
}