func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2e5 + 9;   const int L = 301;   const int INF = 1e9 + 239;   int n;   int a[N];   int cnt[N];   vector<int> pos[N];   int mn[2 * N];   void solve(vector<pair<int, int>> v, int &ans) {     v.push_back({n - 1, 0});     int prev = -1;     int c = 0;     mn[N] = 0;     for (auto [pos, val] : v) {       if (abs(prev) < 2) ans = max(ans, (pos - 1) - mn[c + N] + 1);       c += val;       ans = max(ans, pos - mn[c + N] + 1);       mn[c + N] = min(mn[c + N], pos + 1);       prev = val;     }     c = 0;     mn[0] = INF;     for (auto [pos, val] : v) {       c += val;       mn[c + N] = INF;     }   }   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     fill(mn, mn + 2 * N, INF);     cin >> n;     for (int i = 0; i < n; i++) {       cin >> a[i];       cnt[a[i]]++;       pos[a[i]].push_back(i);     }     int ans = 0;     int mx = max_element(cnt, cnt + N) - cnt;     int pnt = -1;     int sz = -1;     vector<pair<int, int>> vplus, vminus;     auto add = [&](int p) {       int imx = lower_bound(pos[mx].begin(), pos[mx].end(), p) - pos[mx].begin();       int l = max(pnt + 1, imx - (sz + 3));       if (pnt + 1 < imx - (sz + 3)) {         vplus.push_back({pos[mx][pnt + 1], imx - (sz + 3) - (pnt + 1)});       }       for (int i = l; i <= imx + (sz + 3) && i < (int)pos[mx].size(); i++) {         vplus.push_back({pos[mx][i], 1});         pnt = i;       }     };     auto relax_small = [&](int s) {       if (pos[s].empty()) {         return;       }       vplus.clear();       vminus.clear();       sz = (int)pos[s].size();       pnt = -1;       { add(0); }       for (auto p : pos[s]) {         add(p);         vminus.push_back({p, -1});       }       { add(n - 1); }       vector<pair<int, int>> vall(vplus.size() + vminus.size());       merge(vplus.begin(), vplus.end(), vminus.begin(), vminus.end(),             vall.begin());       solve(vall, ans);     };     auto relax_big = [&](int s) {       if (pos[s].empty()) {         return;       }       vplus.clear();       vminus.clear();       for (auto p : pos[mx]) {         vplus.push_back({p, 1});       }       for (auto p : pos[s]) {         vminus.push_back({p, -1});       }       vector<pair<int, int>> vall(vplus.size() + vminus.size());       merge(vplus.begin(), vplus.end(), vminus.begin(), vminus.end(),             vall.begin());       solve(vall, ans);     };     for (int other = 0; other < N; other++) {       if (other == mx) {         continue;       }       if (pos[other].size() > L) {         relax_big(other);       } else {         relax_small(other);       }     }     cout << ans <<   n ;   }   