HDU1505 City Game（悬线法）

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<functional>
#include<string>
#include<algorithm>
#include<iostream>
#include<set>
#include<vector>
#include<queue>
#include<cstdlib>
using namespace std;
const int N=1020;
int l[N][N],r[N][N];
int up[N][N];
int f[N][N];
int a[N][N];
int ans1,ans2;
int main(){
    int i,j,k;
    int n,m;
    int t;
    cin>>t;
    while(t--){
    cin>>n>>m;
    memset(l,0,sizeof l);
    memset(up,0,sizeof up);
    memset(r,0,sizeof r);
    memset(a,0,sizeof a);
    for(i=1;i<=n;i++){
        for(j=1;j<=m;j++){
        char s[5];
        scanf("%s",s);
        if(s[0]==‘F‘){
            a[i][j]=1;
            l[i][j]=r[i][j]=j;
            up[i][j]=1;
        }

        }

    }
    ans1=0;
    for(i=1;i<=n;i++){
        for(j=2;j<=m;j++){
            if(a[i][j]==1&&a[i][j-1]==1)
            l[i][j]=l[i][j-1];
        }
    }
    for(i=1;i<=n;i++){
        for(j=m-1;j>=1;j--){
            if(a[i][j]==1&&a[i][j+1]==1)
            r[i][j]=r[i][j+1];
        }
    }
    for(i=1;i<=n;i++){
        for(j=1;j<=m;j++){
            if(i>1&&a[i][j]==1&&a[i-1][j]==1){
                up[i][j]=up[i-1][j]+1;
                l[i][j]=max(l[i][j],l[i-1][j]);
                r[i][j]=min(r[i][j],r[i-1][j]);
            }
            int a=r[i][j]-l[i][j]+1;
            ans1=max(ans1,3*a*up[i][j]);
        }
    }
    cout<<ans1<<endl;
    }
}