纪中训练5月23日提高组T2

【USACO 2017 US Open Silver】Where’s Bessie?

题解:
暴力出奇迹
先枚举每一个矩阵，然后一个个进行判断
求出每个数字的联通块，之后判断一下有没有被包含

#include
#include
#include
using namespace std;
struct node
{
	int x1,x2,y1,y2;
}a[50005];
int n,i1,i2,j1,j2,num,ans;
int map[25][25],c[10005],color[26];
bool b[25][25];
char ch;
void dg(int x,int i,int j,int i1,int j1,int i2,int j2)
{
	b[i][j]=true;
	if (i<i2&&b[i+1][j]==false&&map[i+1][j]==x) dg(x,i+1,j,i1,j1,i2,j2);
	if (j<j2&&b[i][j+1]==false&&map[i][j+1]==x) dg(x,i,j+1,i1,j1,i2,j2);
	if (i>i1&&b[i-1][j]==false&&map[i-1][j]==x) dg(x,i-1,j,i1,j1,i2,j2);
	if (j>j1&&b[i][j-1]==false&&map[i][j-1]==x) dg(x,i,j-1,i1,j1,i2,j2);
}
bool pd(int xx1,int yy1,int xx2,int yy2)
{
	int i,j,sum;
	sum=0;
	memset(b,false,sizeof(b));
	memset(color,0,sizeof(color));
	memset(c,0,sizeof(c));
	for (i=xx1;i<=xx2;i++)
		for (j=yy1;j<=yy2;j++)
			if (b[i][j]==false)
			{
				if (color[map[i][j]]==0) 
				{
					sum++;
					c[sum]=map[i][j];
				}
				if (sum>2) return false;
				color[map[i][j]]++;
				dg(map[i][j],i,j,xx1,yy1,xx2,yy2);
			}
	if ((color[c[1]]==1&&color[c[2]]>1)||(color[c[2]]==1&&color[c[1]]>1)) return true;
	return false;
}
bool judge(int x)
{
	int i;
	for (i=1;i<=num;i++)
		if (i!=x&&a[i].x1<=a[x].x1&&a[i].y1<=a[x].y1&&a[i].x2>=a[x].x2&&a[i].y2>=a[x].y2) return false;
	return true;
}
int main()
{
	freopen("where.in","r",stdin);
	freopen("where.out","w",stdout);
	scanf("%d",&n);
	for (i1=1;i1<=n;i1++)
		for (j1=1;j1<=n;j1++)
		{
			cin>>ch;
			map[i1][j1]=ch-'A';
		}
	for (i1=1;i1<=n;i1++)
		for (i2=i1;i2<=n;i2++)
			for (j1=1;j1<=n;j1++)
				for (j2=j1;j2<=n;j2++)
					if (pd(i1,j1,i2,j2)==true)
					{
						num++;
						a[num].x1=i1;
						a[num].y1=j1;
						a[num].x2=i2;
						a[num].y2=j2;
					}
	for (i1=1;i1<=num;i1++)
		if (judge(i1)==true) ans++;
	printf("%d\n",ans);
	fclose(stdin);
	fclose(stdout);
	return 0;
}