HDU 1461（Rotations and Reflections）

广搜题，由于情况数很少，依次判断每一种情况即可。

#include 
#include 
using namespace std;
const int MAXN = 15;

struct Node
{
    char mp[MAXN][MAXN]; //图形
    int isReflect; //是否翻转
};

char ed[MAXN][MAXN]; //终止图形
Node now, nex, temp;
int n; //图形边长

//判断node的图形是否为终止图形
bool isEnd(Node node)
{
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (node.mp[i][j] != ed[i][j])
                return false;
        }
    }
    return true;
}

//旋转90°
void rt90()
{
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            now.mp[j][n - i - 1] = nex.mp[i][j];
        }
    }
}

//旋转180°
void rt180()
{
    rt90();
    temp = nex;
    nex = now;
    rt90();
    nex = temp;
}

//旋转270°
void rt270()
{
    rt90();
    temp = nex;
    nex = now;
    rt90();
    nex = now;
    rt90();
    nex = temp;
}

//翻转
void reflect()
{
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            now.mp[n - i - 1][j] = nex.mp[i][j];
        }
    }
}

//广搜
void BFS()
{
    queue q;
    if (isEnd(now))
    {
        cout << "Preserved" << endl;
        return;
    }
    now.isReflect = 0;
    q.push(now);
    while (!q.empty())
    {
        nex = q.front();
        q.pop();
        if (nex.isReflect == 0) //未翻转
        {
            now.isReflect = 1;
            rt90();
            if (isEnd(now))
            {
                cout << "Rotated through 90 degrees" << endl;
                return;
            }
            rt180();
            if (isEnd(now))
            {
                cout << "Rotated through 180 degrees" << endl;
                return;
            }
            rt270();
            if (isEnd(now))
            {
                cout << "Rotated through 270 degrees" << endl;
                return;
            }
            reflect();
            if (isEnd(now))
            {
                cout << "Reflected" << endl;
                return;
            }
            q.push(now);
        }
        else if (nex.isReflect == 1) //已翻转
        {
            rt90();
            if (isEnd(now))
            {
                cout << "Reflected and rotated through 90 degrees" << endl;
                return;
            }
            rt180();
            if (isEnd(now))
            {
                cout << "Reflected and rotated through 180 degrees" << endl;
                return;
            }
            rt270();
            if (isEnd(now))
            {
                cout << "Reflected and rotated through 270 degrees" << endl;
                return;
            }
            cout << "Improper" << endl;
        }
    }
}

int main()
{
    while (cin >> n)
    {
        if (n == 0)
            break;
        for (int i = 0; i < n; i++)
        {
            cin >> now.mp[i] >> ed[i];
        }
        BFS();
    }
    return 0;
}

继续加油。