BZOJ-1085 骑士精神

估价函数其实就是与目标状态有几个不同。。。

迭代启发搜索。

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <fstream>
#include <iostream>
#include <queue>

#define rep(i, l, r) for(int i = l; i <= r; i++)
#define down(i, l, r) for(int i = l; i >= r; i--)
#define maxn 123
#define MAX 1<<30;

using namespace std;

int n[6][6], k, x, y;
char s[9];

int F()
{
	int c = 0;
	rep(i, 1, 5) if (n[1][i] == 0) c++;
	rep(i, 2, 5) if (n[2][i] == 0) c++;
	rep(i, 4, 5) if (n[3][i] == 0) c++;
	if (n[4][5] == 0) c++;
	rep(i, 1, 5) if (n[5][i] == 1) c++;
	rep(i, 1, 4) if (n[4][i] == 1) c++;
	rep(i, 1, 3) if (n[3][i] == 1) c++;
	if (n[2][1] == 1) c++;
	return c;
}

bool Search(int x, int y, int c)
{
	if (!c && x == 3 && y == 3 && !F()) return true;
	if (c < F()-1) return false;
	//int now = F(), a;
	int a;
	if (x > 2 && y > 1)
	{
		a = n[x-2][y-1]; n[x-2][y-1] = n[x][y]; n[x][y] = a;
		if (Search(x-2, y-1, c-1)) return true;
		a = n[x-2][y-1]; n[x-2][y-1] = n[x][y]; n[x][y] = a;
	}
	if (x > 1 && y > 2)
	{
		a = n[x-1][y-2]; n[x-1][y-2] = n[x][y]; n[x][y] = a;
		if (Search(x-1, y-2, c-1)) return true;
		a = n[x-1][y-2]; n[x-1][y-2] = n[x][y]; n[x][y] = a;
	}
	if (x < 5 && y > 2)
	{
		a = n[x+1][y-2]; n[x+1][y-2] = n[x][y]; n[x][y] = a;
		if (Search(x+1, y-2, c-1)) return true;
		a = n[x+1][y-2]; n[x+1][y-2] = n[x][y]; n[x][y] = a;
	}
	if (x < 4 && y > 1)
	{
		a = n[x+2][y-1]; n[x+2][y-1] = n[x][y]; n[x][y] = a;
		if (Search(x+2, y-1, c-1)) return true;
		a = n[x+2][y-1]; n[x+2][y-1] = n[x][y]; n[x][y] = a;
	}
	if (x < 4 && y < 5)
	{
		a = n[x+2][y+1]; n[x+2][y+1] = n[x][y]; n[x][y] = a;
		if (Search(x+2, y+1, c-1)) return true;
		a = n[x+2][y+1]; n[x+2][y+1] = n[x][y]; n[x][y] = a;
	}
	if (x < 5 && y < 4)
	{
		a = n[x+1][y+2]; n[x+1][y+2] = n[x][y]; n[x][y] = a;
		if (Search(x+1, y+2, c-1)) return true;
		a = n[x+1][y+2]; n[x+1][y+2] = n[x][y]; n[x][y] = a;
	}
	if (x > 2 && y < 5)
	{
		a = n[x-2][y+1]; n[x-2][y+1] = n[x][y]; n[x][y] = a;
		if (Search(x-2, y+1, c-1)) return true;
		a = n[x-2][y+1]; n[x-2][y+1] = n[x][y]; n[x][y] = a;
	}
	if (x > 1 && y < 4)
	{
		a = n[x-1][y+2]; n[x-1][y+2] = n[x][y]; n[x][y] = a;
		if (Search(x-1, y+2, c-1)) return true;
		a = n[x-1][y+2]; n[x-1][y+2] = n[x][y]; n[x][y] = a;
	}
	return false;
}

int main()
{
	int t; scanf("%d", &t);
	while (t--)
	{
		rep(i, 1, 5)
		{
			scanf("%s", s);
			rep(j, 1, 5)
				if (s[j-1] == '*') x = i, y = j, n[i][j] = 0;
				else if (s[j-1] == '0') n[i][j] = 0;
				else n[i][j] = 1;
		}
		k = 0;
		while (k <= 15) if (Search(x, y, k)) break; else k++;
		if (k == 16) k = -1; printf("%d\n", k);
	}
}