hdu 1505 最大子矩阵

#include<iostream>#include<algorithm>#include<cstdio>#include<memory.h>using namespace std;const int maxn=1002;int n,m,t,ans,cas=1;int h[maxn][maxn];///h[i,j]为点(i,j)对应的悬线的长度。int l[maxn];///l[i,j]为点(i,j)对应的悬线向左最多能够移动到的位置。int r[maxn];///r[i,j]为点(i,j)对应的悬线向右最多能够移动到的位置。char g[2];///图像int main(){    //freopen("//media/学习/ACM/input.txt","r",stdin);    scanf("%d",&t);    int i,j;    while(t--)    {        scanf("%d%d",&n,&m);        for(ans=-1,i=1;i<=m;i++)h[0][i]=0;        for(i=1;i<=n;i++)        {            for(j=1;j<=m;j++)            {               scanf("%s",g);               if(g[0]=='F')                   h[i][j]=h[i-1][j]+1;                else h[i][j]=0;            }        }        for(i=1;i<=n;i++)        {            h[i][0]=h[i][m+1]=-1;            for(j=1;j<=m;j++)l[j]=r[j]=j;            for(j=2;j<=m;j++)            {                while(h[i][l[j]-1]>=h[i][j])l[j]=l[l[j]-1];            }            for(j=m-1;j>=1;j--)            {                while(h[i][r[j]+1]>=h[i][j])r[j]=r[r[j]+1];            }            for(j=1;j<=m;j++)            {                 if (h[i][j]*(r[j]-l[j]+1)>ans) ans=h[i][j]*(r[j]-l[j]+1);            }        }        printf("%d\n",ans*3);    }    return 0;}