【NOIP 2011】 Mayan游戏

【题目链接】

           https://www.luogu.org/problemnew/show/P1312

【算法】

            深度优先搜索

【代码】

           

#include<bits/stdc++.h>
using namespace std;

struct info
{
        int x,y,op;
} step[10];

int i,n,t,x;
int a[10][10];
bool solved;

inline void print()
{
        int i;
        for (i = 1; i <= n; i++) printf("%d %d %d\n",step[i].x - 1,step[i].y - 1,step[i].op);
}
inline bool check()
{
        int i;
        for (i = 1; i <= 5; i++)
        {
                if (a[i][1] != 0)
                        return false;
        }
        return true;
}
inline bool Remove()
{
        int i,j,x,y,t;
        bool ret = false;
        bool d[10][10];
        memset(d,false,sizeof(d));
        for (i = 1; i <= 5; i++)
        {
                for (j = 1; j <= 7; j++)
                {
                        if (a[i][j])
                        {
                                for (x = j + 1; a[i][j] == a[i][x] && x <= 7; x++);
                                if (x - j >= 3)
                                {
                                        for (y = j; y < x; y++)
                                                d[i][y] = true;
                                        ret = true;
                                }
                                for (x = i + 1; a[i][j] == a[x][j] && x <= 5; x++);
                                if (x - i >= 3)
                                {
                                        for (y = i; y < x; y++)
                                                d[y][j] = true;
                                        ret = true;
                                }
                        }
                }
        }
        for (i = 1; i <= 5; i++)
        {
                for (j = 1; j <= 7; j++)
                {
                        if (d[i][j])
                                a[i][j] = 0;
                }
        }
        for (i = 1; i <= 5; i++)
        {
                t = 0;
                for (j = 1; j <= 7; j++)
                {
                        if (!a[i][j])
                        {
                                for (x = j + 1; x <= 7 && !a[i][x]; x++);
                                a[i][j] = a[i][x];
                                a[i][x] = 0;
                        }
                }                
        }
        return ret;
}

inline void dfs(int dep)
{
        int i,j,x,y;
        int b[10][10];
        if (dep > n)
        {
                if (check())
                {
                        solved = true;
                        print();
                }
                return;        
        }        
        for (i = 1; i <= 5; i++)
        {
                for (j = 1; j <= 7; j++)
                {
                        b[i][j] = a[i][j];    
                }
        }
        for (i = 1; i <= 5; i++)
        {
                for (j = 1; j <= 7; j++)
                {
                        if (i < 5 && a[i][j] != 0)
                        {
                                if (a[i+1][j] != 0)
                                {
                                        step[dep] = (info){i,j,1};
                                        swap(a[i][j],a[i+1][j]);
                                        while (Remove());
                                        dfs(dep+1);
                                        if (solved) return;
                                        for (x = 1; x <= 5; x++)
                                        {
                                                for (y = 1; y <= 7; y++)
                                                {
                                                        a[x][y] = b[x][y];
                                                }
                                        }
                                } else
                                {
                                        step[dep] = (info){i,j,1};
                                        for (x = j - 1; x >= 1 && !a[i+1][x]; x--);
                                        a[i+1][x+1] = a[i][j];
                                        for (x = j; x <= 7; x++) a[i][x] = a[i][x+1];
                                        while (Remove());  
                                        dfs(dep+1);
                                        if (solved) return;
                                        for (x = 1; x <= 5; x++)
                                        {
                                                for (y = 1; y <= 7; y++)
                                                {
                                                        a[x][y] = b[x][y];
                                                }
                                        }
                                }
                        } 
                        if (i > 1 && a[i][j] != 0)
                        {
                                if (a[i-1][j] == 0)
                                {
                                        step[dep] = (info){i,j,-1};
                                        for (x = j - 1; x >= 1 && !a[i-1][x]; x--);
                                        a[i-1][x+1] = a[i][j];
                                        for (x = j; x <= 7; x++) a[i][x] = a[i][x+1];
                                        while (Remove());
                                        dfs(dep+1);
                                        if (solved) return;
                                        for (x = 1; x <= 5; x++)
                                        {
                                                for (y = 1; y <= 7; y++)
                                                {
                                                        a[x][y] = b[x][y];
                                                }
                                        }
                                }
                        }
                }
        }
}

int main() 
{
        
        scanf("%d",&n);
        for (i = 1; i <= 5; i++)
        {
                t = 0;
                while (scanf("%d",&x) && x)
                        a[i][++t] = x;    
        }
        solved = false;
        dfs(1);
        if (!solved) printf("-1\n");
        
        return 0;
    
}