蓝桥杯2017年第八届真题-九宫幻方(C++)

知道上图进行若干镜像和旋转操作之后，一共可以形成8种答案，这道题就好解许多

#include<iostream>
using namespace std;
int arr[9];
//所有情况
int all[8][9] = { {4,9,2,3,5,7,8,1,6},//原始
                  {8,1,6,3,5,7,4,9,2},//上下翻折
                  {2,9,4,7,5,3,6,1,8},//左右翻折
                  {8,3,4,1,5,9,6,7,2},//右旋
                  {4,3,8,9,5,1,2,7,6},//右旋之左右翻折
                  {6,7,2,1,5,9,8,3,4},//右旋之上下翻折
                  {6,1,8,7,5,3,4,9,2},//再右旋
                  {2,7,6,9,5,1,4,3,8},//再右旋
                };
int test(int arr[]) 
{
    int cnt = 0, pos = -1;//cnt计数,pos纪录当仅能还原出一组可行的三阶幻方时，在all[][]数组中的行下标
    for (int i = 0; i < 8; i++) {
        bool OK = true;
        for (int j = 0; j < 9; j++) {
            if (arr[j] == 0)  continue;//遇到0时跳过
            if (arr[j] != all[i][j]) {//与all[][]第i行不匹配时，跳到下一行继续判定
                OK = false;
                break;
            }
        }
        if (OK) {//如果匹配，个数+1，记录行下标
            cnt++;
            pos = i;
        }
    }
    if (cnt == 1)//只有一个匹配
        return pos;
    else
        return -1;
}
int main()
{
    for (int i = 0; i < 9; i++)
        cin >> arr[i];
    int index = test(arr);
    if (index == -1)
        cout << "Too Many" << endl;
    else {
        cout << all[index][0] << " " << all[index][1] << " " << all[index][2] << endl;
        cout << all[index][3] << " " << all[index][4] << " " << all[index][5] << endl;
        cout << all[index][6] << " " << all[index][7] << " " << all[index][8] << endl;
    }
    return 0;
}