$% w, h, fillcol, bordercol \newcommand\BorderRect[4]{ \color{#3}\rule{#1}{#2}\kern{-#1} \color{#4}\rule{0.5px}{#2}\kern{-0.5px} \rule{#1}{0px}\rule{0.5px}{#2}\kern{-0.5px} \kern{-#1}\rule[#2]{#1}{0px} } % w, h, title, subtitle, fillcol, iconch ,iconcol \newcommand\BasicInfoBarFather[8]{ \BorderRect{#1}{#2}{#5}{ghostwhite} \kern{-#1} \raisebox{#2}{ \raisebox{-26pt}{ \color{black}\kern{-4px} \raisebox{7px}{ \color{#7}\Huge{∙}\kern{-1px} } \raisebox{10.6px}{ \kern{-20.2px} \color{white}\scriptsize\textbf{#6} } \kern{-7px}\footnotesize \raisebox{10.2px}{\textbf{\textsf{\color{#8}#3}}}\kern{2px} \raisebox{10.2px}{\textsf{#4}} } } } \def\BasicInfoBarColorFill{#F4F4F4}\def\BasicInfoBarColorIcon{#0078D4} \def\BasicWarnBarColorFill{#FFF4CE}\def\BasicWarnBarColorIcon{#9D5D00} \def\BasicOkBarColorFill{#DFF6DD}\def\BasicOkBarColorIcon{#0F7B0F} \def\BasicErrBarColorFill{#FDE7E9}\def\BasicErrBarColorIcon{#C42B1C} \newcommand\BasicInfoBar[5]{ \BasicInfoBarFather{#1}{#2}{#3}{#4} {\BasicInfoBarColorFill}{i}{\BasicInfoBarColorIcon}{\BasicInfoBarColorIcon} } \newcommand\BasicWarnBar[5]{ \BasicInfoBarFather{#1}{#2}{#3}{#4} {\BasicWarnBarColorFill}{i}{\BasicWarnBarColorIcon}{\BasicWarnBarColorIcon} } \newcommand\BasicOkBar[5]{ \BasicInfoBarFather{#1}{#2}{#3}{#4} {\BasicOkBarColorFill} {\tiny\kern{-2px}\raisebox{0.8px}{√}} {\BasicOkBarColorIcon}{\BasicOkBarColorIcon} } \newcommand\BasicErrBar[5]{ \BasicInfoBarFather{#1}{#2}{#3}{#4} {\BasicErrBarColorFill} {\kern{-2px}\raisebox{0.6px}{×}} {\BasicErrBarColorIcon}{\BasicErrBarColorIcon} } \BasicWarnBar{200px}{26px}{ 警告}{此人太蒻了，请小心}{#000000}\\ \BasicInfoBar{200px}{26px}{ 提醒}{近蒻者蒻}{#000000}\\ \BasicErrBar{200px}{26px}{请勿}{膜拜我}{#000000}\\ \BasicOkBar{200px}{26px}{应该}{嘲讽并踩爆这个蒟蒻}{#000000}\\$

你是第个看我主页的人

善良一波：

#include <bits/stdc++.h>

#define int long long
#define endl "\n"
using namespace std;
int n,m,mat[1010][1010],l[1010],r[1010],ans=-1e18;
char c[1010][1010];
stack<int> s;
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    //freopen("xxx.in","r",stdin);
    //freopen("xxx.out","w",stdout);
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> c[i][j];
            if (c[i][j] == 'R') mat[i][j] = 0;
            else mat[i][j] = 1;
        }
    }
    vector<int> f(m + 1);
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) r[j] = m + 1;
        for (int j = 1; j <= m; j++) {
            if (mat[i][j]) f[j]++;
            else f[j] = 0;
        }
        for (int j = 1; j <= m; j++) {
            while (!s.empty() && f[s.top()] >= f[j]) s.pop();
            if (!s.empty()) l[j] = s.top();
            s.push(j);
        }
        while (!s.empty()) s.pop();
        for (int j = m; j >= 1; j--) {
            while (!s.empty() && f[s.top()] >= f[j]) s.pop();
            if (!s.empty()) r[j] = s.top();
            s.push(j);
        }
        while (!s.empty()) s.pop();
        for (int j = 1; j <= m; j++) {
            ans = max(ans, f[j] * (r[j] - l[j] - 1));
        }
    }
    cout << 3 * ans << endl;
    return 0;
}