noip提高组2011 mayan游戏

[lrj124]

这题主要难点不在搜索，而在如何消除联通的块和让快掉落，搜索还是挺好写的，还可以在搜的时后加个剪枝：若有一种颜色块只有一或两块，直接return

#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using std :: swap;
int s[6][8],n;
struct T {
  int x,y,z;
}ans[6];
inline bool check(int tmp[6][8]) {
  bool pd[6][8],flag = false;
  memset(pd,false,sizeof(pd));
  for (int i = 0;i <= 5;i++)
	for (int j = 0;j <= 7;j++)
	  if (tmp[i][j]) {
	    if (i <= 3 && tmp[i][j] == tmp[i+1][j] && tmp[i+1][j] == tmp[i+2][j]) pd[i][j] = pd[i+1][j] = pd[i+2][j] = true;  //标记起来相同的（列）
		if (j <= 5 && tmp[i][j] == tmp[i][j+1] && tmp[i][j+1] == tmp[i][j+2]) pd[i][j] = pd[i][j+1] = pd[i][j+2] = true;  //标记起来相同的（行）
	  }
  for (int i = 0;i < 5;i++)
	for (int j = 0;j < 7;j++)
	  if (pd[i][j]) {
	    tmp[i][j] = 0;  //消掉
		flag = true;
      }
  return flag;
}
inline void down(int tmp[6][8]) {
  for (int i = 0;i < 5;i++) {
	int t = 0;
	for(int j = 0;j < 7;j++) {
	  int l = tmp[i][j];
	  tmp[i][j] = 0;
	  if (l) tmp[i][t++] = l;  //掉落
	}
  }
}
void dfs(int tot,int map[6][8]) {
  if (tot == n) {
    bool flag = true;
	for (int i = 0;i < 5;i++)
      for (int j = 0;j < 7;j++)
	    if (map[i][j]) {
		  flag = false;
	      break;
		}
	if (flag) {  //是否消完
	  for (int i = 1;i <= n;i++) printf("%d %d %d\n",ans[i].x,ans[i].y,ans[i].z);
      exit(false);
    }
	return;  
  }
  int cnt[11];
  memset(cnt,0,sizeof(cnt));
  for (int i = 0;i < 5;i++)
    for (int j = 0;j < 7;j++) cnt[map[i][j]]++;  //统计每种颜色有多少块
  for (int i = 1;i <= 10;i++)
    if (cnt[i] == 1 || cnt[i] == 2) return;  //若不足三块，直接return
  for (int i = 0;i < 4;i++)
	for (int j = 0;j < 7;j++)
	  if (map[i][j] != map[i+1][j]) {  //把不一样的两个相邻块交换
	    int tmp[6][8];
	    memcpy(tmp,map,sizeof(tmp));
		if (tmp[i][j]) {
	      ans[tot+1].x = i;
		  ans[tot+1].y = j;
		  ans[tot+1].z = 1;
		} else {
	      ans[tot+1].x = i+1;
		  ans[tot+1].y = j;
		  ans[tot+1].z = -1;
		}
		swap(tmp[i][j],tmp[i+1][j]);  //交换
		down(tmp);  //掉落
		while (check(tmp)) down(tmp);  //消掉，然后掉落
		dfs(tot+1,tmp);  //下一步
	  }
}
int main() {
  freopen("mayan.in","r",stdin);
  freopen("mayan.out","w",stdout);
  scanf("%d",&n);
  for (int i = 0;i < 5;i++) {  //读入
    int x,t = 0;
	read : scanf("%d",&x);
	if (x) {
	  s[i][t++] = x;
	  goto read;
	}
  }
  dfs(0,s);
  printf("-1");  //无解输出-1
  return 0;
}