C++将数组的元素顺序随机打乱

参考：

https://blog.csdn.net/cordova/article/details/52884399

https://zhidao.baidu.com/question/1604258083773493627.html

自己的测试代码

    int array1[] = {,,,,,,,,};

    int array2[] = {  };

    for (int i=;i>;i--)
    {
        int pos = rand() % i;
        printf("%d ", pos);

        array2[i] = array1[pos];

        for (int j = pos;j<;j++)
        {
            array1[j] = array1[j+];
        }
    }

    array2[] = array1[];

    printf("\n");
    for (int i = ; i<  ; i++)
    {
        printf("%d ", array2[i]);
    }

打乱之后，恢复：

#include<iostream>
using namespace std;
int main()
{
    char str[]="abcdefg123456789";
    char key[]="";
    char temp;
    /*利用秘钥乱序*/
    for(int j = ; j < ; j++)   //对于key的前两位
        for(int i = ;(i+(key[j]-''))<=; i++)
        {
                if(i%!=)//奇数位与其后面第key[j]位交换
                {
                temp = str[i+(key[j]-'')];
                str[i+(key[j]-'')] = str[i];
                str[i] = temp;
                }
        }
    for(int i = ; i < ; i++)
        cout<<str[i]<<" ";
    cout<<endl;
    for(int j = ; j < ; j++)    //对于key的后两位
        for(int i = ;(i+(key[j]-''))<=; i++)
        {
            if(i%==)//偶数位与其后面第key[j]位交换
            {
                temp = str[i+(key[j]-'')];
                str[i+(key[j]-'')] = str[i];
                str[i] = temp;
                }
        }
    for(int i = ; i < ; i++)
        cout<<str[i]<<" ";
    cout<<endl;

    /*利用秘钥复原*/
    for(int j = ; j >= ; j--)    //对于key的后两位
        for(int i = ;(i-(key[j]-''))>=; i--)
        {
            if(i%!=)//奇数位与其前面第key[j]位交换
            {
                temp = str[i-(key[j]-'')];
                str[i-(key[j]-'')] = str[i];
                str[i] = temp;
                }
        }
    for(int i = ; i < ; i++)
        cout<<str[i]<<" ";
    cout<<endl;

    for(int j = ; j >= ; j--)   //对于key的前两位
        for(int i = ;(i-(key[j]-''))>=; i--)
        {
                if(i%!=)//奇数位与其前面第key[j]位交换
                {
                temp = str[i-(key[j]-'')];
                str[i-(key[j]-'')] = str[i];
                str[i] = temp;
                }
        }
    for(int i = ; i < ; i++)
        cout<<str[i]<<" ";
    system("pause");
    return ;
}