【P1738】NOIP2011Mayan游戏C++题解（搜索）

这搜索真的挺麻烦的

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxx = 5 + 5, maxy = 7 + 5, maxc = 10 + 5;
int n, c;
int a[maxx][maxy], cnt[maxc];
bool f[maxx][maxy];
int ans[maxx][3];

void fall(int x)
{
for (int i = 0; i < 7; i++)
{ if (a[x][i] == 0)
{ int j = i + 1;
while (j < 7 && a[x][j] == 0) j++;
if ( j == 7) return;
else swap(a[x][i], a[x][j]);
}
}
}

bool clear()
{
bool flag = false;
for (int i = 0; i < 5; i++)
for (int j = 0; j < 7; j++)
{ if (!a[i][j]) continue;
if ( i < 3 && a[i][j] == a[i+1][j] && a[i][j] == a[i+2][j])
{ f[i][j] = true; f[i+1][j] = true; f[i+2][j] = true;}
if ( j < 5 && a[i][j] == a[i][j+1] && a[i][j] == a[i][j+2])
{ f[i][j] = true; f[i][j+1] = true; f[i][j+2] = true;}
}
for (int i = 0; i < 5; i++)
for (int j = 0; a[i][j] && j < 7; j++)
if (f[i][j])
{
flag = true;
cnt[a[i][j]]--;
a[i][j] = 0;
f[i][j] = 0;
}
for (int i = 0; i < 5; i++)
fall(i);
return flag;
}

int check()
{
int minc = 0;
for (int i = 1; i <= c; i++)
if (cnt[i])
if (!minc || minc > cnt[i])
minc = cnt[i];
return minc;
}

void print()
{
for (int i = 1; i <= n; i++)
printf("%d %d %d\n", ans[i][0], ans[i][1], ans[i][2]);
exit(0);
}
void dfs(int move)
{

int mem[maxx][maxy], memc[maxc];
for (int i = 0; i < 5; i++)
for (int j = 0; j < 7; j++)
mem[i][j] = a[i][j];
for (int i = 1; i <= c; i++)
memc[i] = cnt[i];
//数据复制

for (int i = 0; i < 5; i++)
for (int j = 0; a[i][j] && j < 7; j++)
for (int k = 1; k >= -1; k-=2)
if (i+k >= 0 && i+k < 5)
{
if ((k == -1 && a[i-1][j]) || a[i][j] == a[i+k][j]) continue;
ans[move][0] = i; ans[move][1] = j; ans[move][2] = k;
swap(a[i][j], a[i+k][j]);
fall(i); fall(i+k);//检测下落合法性
while (clear());//合并
int tmp = check();//返回的值为最少的颜色块数
if (move == n)
{ if (tmp == 0) print();//如果是已经完成
}
else if (tmp > 2) dfs(move+1);//至少存在三个，继续合并

for (int i = 0; i < 5; i++)//后续处理，数据恢复
for (int j = 0; j < 7; j++)
a[i][j] = mem[i][j];
for (int i = 1; i <= c; i++)
cnt[i] = memc[i];
}

}

int main()
{
scanf("%d", &n);
memset(a, 0, sizeof(a));
memset(cnt, 0, sizeof(cnt));
memset(ans, 0, sizeof(ans));
memset(f, 0, sizeof(f));
c = 0;
int tmp;
for (int i = 0; i < 5; i++)
for (int j = 0; j <= 7; j++)
{ scanf("%d", &tmp);
if (tmp == 0)
break;
a[i][j] = tmp;
c = max(c, tmp);
cnt[tmp]++;
}

dfs(1);
printf("-1\n");
return 0;
}