Hdu 5024 Wang Xifeng's Little Plot（暴力枚举）

题目地址：http://acm.hdu.edu.cn/showproblem.php?pid=5024
思路：枚举每个‘.’点，分两种情况：横竖、对角线。从该点分别向某一方向延伸到最大，从横竖中取两个最大值；从对角线中取两个最大值，最后取两种情况的最大值即为解。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int maxn=100+50;
const int INF=0x3f3f3f3f;
const int dx1[]={1,-1,0,0};
const int dy1[]={0,0,-1,1};
const int dx2[]={1,-1,1,-1};
const int dy2[]={1,-1,-1,1};
int n;
int g[maxn][maxn];
int Find1(int x,int y)
{
int tmp[4];
memset(tmp,0,sizeof(tmp));
for(int i=0;i<4;i++)
{
int xx=x,yy=y;
for(;;)
{
xx+=dx1[i];
yy+=dy1[i];
if(xx<1||xx>n||yy<1||yy>n||g[xx][yy]=='#') break;
// cout<<xx<<" "<<yy<<" "<<tmp[i]<<" "<<n<<endl;
tmp[i]++;
}
}
sort(tmp,tmp+4);
return tmp[2]+tmp[3];
}
int Find2(int x,int y)
{
int tmp[4];
memset(tmp,0,sizeof(tmp));
for(int i=0;i<4;i++)
{
int xx=x,yy=y;
for(;;)
{
xx+=dx2[i];
yy+=dy2[i];
if(xx<1||xx>n||yy<1||yy>n||g[xx][yy]=='#') break;
tmp[i]++;
}
}
sort(tmp,tmp+4);
return tmp[2]+tmp[3];
}
int main()
{
while(scanf("%d",&n)!=EOF&&n)
{
getchar();
for(int i=1; i<=n; i++)
{
for(int j=1; j<=n; j++)
scanf("%c",&g[i][j]);
getchar();
}
int ans=-INF;
for(int i=1; i<=n; i++)
for(int j=1; j<=n; j++)
{
if(g[i][j]!='#')
{
ans=max(ans,Find1(i,j));
ans=max(ans,Find2(i,j));
//cout<<Find1(i,j)<<" "<<Find2(i,j)<<endl;
}
}
printf("%d\n",ans+1);
}
return 0;
}