【IDA*】P2324 [SCOI2005]骑士精神

#include<iostream>
#include<cstdio>
using namespace std;

int g[6][6] =
{
    {0,0,0,0,0,0},
    {0,1,1,1,1,1},
    {0,0,1,1,1,1},
    {0,0,0,2,1,1},
    {0,0,0,0,0,1},
    {0,0,0,0,0,0}
};

int a[6][6];

int xx[8] = { 1,-1,2,-2,1,-1,2,-2 };
int yy[8] = { 2,2,1,1,-2,-2,-1,-1 };

int pre()
{
    int re = 0;
    for (int i = 1; i <= 5; i++)
    {
        for (int j = 1; j <= 5; j++)
        {
            if (a[i][j] != g[i][j]) re++;
        }
    }
    return re;
}

bool ida(int maxd, int d, int x, int y)
{
    int t = pre();
    if (!t) return true;
    if (t + d - 1 > maxd) return false;
    for (int i = 0; i < 8; i++)
    {
        if (x + xx[i] < 1 || x + xx[i]>5 || y + yy[i] < 1 || y + yy[i]>5) continue;
        swap(a[x + xx[i]][y + yy[i]], a[x][y]);
        if (ida(maxd, d + 1, x + xx[i], y + yy[i])) return true;
        swap(a[x + xx[i]][y + yy[i]], a[x][y]);
    }
    return false;
}

int T;

int main()
{
    cin >> T;
    cin.ignore(0x3f, '\n');
    while (T--)
    {
        int x, y;
        for (int i = 1; i <= 5; i++)
        {
            char t[10];
            scanf(" %s", t + 1);
            //scanf_s(" %s", t + 1, 6);
            for (int j = 1; j <= 5; j++)
            {
                a[i][j] = t[j] - '0';
                if (a[i][j] && a[i][j] - 1)
                {
                    a[i][j] = 2;
                    x = i;
                    y = j;
                }
            }
        }
        bool flag = false;
        for (int i = 1; i <= 15; i++)
        {
            if (ida(i, 0, x, y))
            {
                cout << i << endl;
                flag = true;
                break;
            }
        }
        if(!flag) cout << -1 << endl;
    }
}