悬线法 || BZOJ3039: 玉蟾宫 || Luogu P4147 玉蟾宫

题面： P4147 玉蟾宫

题解：过于板子举报了

#include<cstdio>
#include<cstring>
#include<iostream>
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
using namespace std;
const int maxn=1050,maxm=maxn;
int N,M,L[maxn][maxm],R[maxn][maxm],H[maxn][maxm],ans=0;
char c,C[maxn][maxm];
int main(){
    scanf("%d%d",&N,&M);
    for(int i=1;i<=N;i++){
        for(int j=1;j<=M;j++){
            c=getchar();
            while(c!='R'&&c!='F')c=getchar();
            C[i][j]=c;
        }
    }
    for(int i=1;i<=N;i++){
        for(int j=1;j<=M;j++){
            if(C[i][j]=='F')H[i][j]=H[i-1][j]+1;
            else H[i][j]=0;
            if(C[i][j]=='F')L[i][j]=L[i][j-1]+1;
            else L[i][j]=0;
            int r=M-j+1;
            if(C[i][r]=='F')R[i][r]=R[i][r+1]+1;
            else R[i][r]=0;
        }
    }
    for(int i=1;i<=N;i++){
        for(int j=1;j<=M;j++){
            if(H[i][j]>1){
                L[i][j]=min(L[i][j],L[i-1][j]);
                R[i][j]=min(R[i][j],R[i-1][j]);
            }
            ans=max(ans,(L[i][j]+R[i][j]-1)*H[i][j]);
        }
    }
    ans*=3;
    printf("%d
",ans);
    return 0;
}

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By:AlenaNuna