1287. Mars Canals 夜

http://acm.timus.ru/problem.aspx?space=1&num=1287

我说Timus  你还能再水一些吗 递推 + 滚动数组

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
#include <algorithm>

#define LL long long

//#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
const int N=1500;
char s[N][N];
struct node
{
    int ud,lr,k1,k2;
}ans[2][N];
int Snum,snum;
int Fmax4(int a,int b,int c,int d)
{
    if(a<b)
    a=b;
    if(a<c)
    a=c;
    if(a<d)
    a=d;
    return a;
}
int main()
{
    //freopen("data.txt","r",stdin);
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        memset(s,0,sizeof(s));
        for(int i=1;i<=n;++i)
        {
            getchar();
            for(int j=1;j<=n;++j)
            {
                scanf("%c",&s[i][j]);
            }
        }
        Snum=0,snum=0;
        for(int i=1;i<=n;++i)
        {
            int l=i%2;
            int l1=(i-1)%2;
            for(int j=1;j<=n;++j)
            {
                ans[l][j].k1=1;
                ans[l][j].ud=1;
                ans[l][j].lr=1;
                if(s[i][j]==s[i-1][j])
                {
                    ans[l][j].ud=ans[l1][j].ud+1;
                }
                if(s[i][j]==s[i][j-1])
                {
                    ans[l][j].lr=ans[l][j-1].lr+1;
                }
                if(s[i][j]==s[i-1][j-1])
                {
                    ans[l][j].k1=ans[l1][j-1].k1+1;
                }
                if(s[i][j]=='S')
                Snum=Fmax4(Snum,ans[l][j].lr,ans[l][j].ud,ans[l][j].k1);
                else
                snum=Fmax4(snum,ans[l][j].lr,ans[l][j].ud,ans[l][j].k1);

            }
            for(int j=n;j>=1;--j)
            {
                ans[l][j].k2=1;
                if(s[i][j]==s[i-1][j+1])
                {
                    ans[l][j].k2=ans[l1][j+1].k2+1;
                }
                if(s[i][j]=='S')
                Snum=max(Snum,ans[l][j].k2);
                else
                snum=max(snum,ans[l][j].k2);
            }
        }

        //cout<<Snum<<" "<<snum<<endl;
        if(Snum>snum)
        {
            printf("S\n%d\n",Snum);
        }else if(snum>Snum)
        {
            printf("s\n%d\n",snum);
        }else
        {
            printf("?\n%d",snum);
        }
    }
    return 0;
}