func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, cnt[200200], mx = 0, val = 0, arr[200200], pr[200200], a[200200], ans;   vector<int> lst, bd;   void tryBuild(int i) {     vector<int> lPos(400400, -1);     lPos[200000] = 0;     for (int i1 = 1; i1 <= n; i1++) {       if (a[i1] == i) {         arr[i1] = 1;       } else {         if (a[i1] != val) {           arr[i1] = 0;         }       }       pr[i1] = pr[i1 - 1] + arr[i1];       if (lPos[pr[i1] + 200000] == -1) {         lPos[pr[i1] + 200000] = i1;       } else {         ans = max(ans, i1 - lPos[pr[i1] + 200000]);       }     }   }   vector<vector<int> > pose(200200);   int pref[200200];   int num[200200];   void solve() {     cin >> n;     for (int i = 1; i <= n; i++) {       cin >> a[i];       cnt[a[i]]++;       if (cnt[a[i]] > mx) {         mx = cnt[a[i]];         val = a[i];       }       pose[a[i]].push_back(i);     }     for (int i = 1; i <= n; i++) {       if (cnt[i] >= (int)sqrt(n)) {         lst.push_back(i);       } else {         bd.push_back(i);       }     }     for (int i = 1; i <= n; i++) {       pref[i] = pref[i - 1];       if (a[i] == val) {         arr[i] = -1;         pref[i]++;         num[pref[i]] = i;       }     }     for (auto i : lst) {       if (i == val) {         continue;       }       tryBuild(i);     }     for (auto ch : bd) {       if (ch == val) {         continue;       }       for (int i = 0; i < pose[ch].size(); i++) {         int x = pose[ch][i];         for (int i1 = pose[ch].size() - 1; i1 >= i; i1--) {           int y = pose[ch][i1];           int cnt = i1 - i + 1 - (pref[y] - pref[x - 1]);           if (cnt < 0) {             continue;           }           int be = pref[x - 1];           int all = pref[y];           for (int i2 = 0; i2 <= cnt; i2++) {             int l = (be < i2 ? 1 : num[be - i2] + 1);             int r = (cnt - i2 + all >= mx ? n : num[cnt - i2 + all + 1] - 1);             ans = max(ans, r - l + 1);           }         }       }     }     cout << ans;   }   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     int q;     q = 1;     while (q != 0) {       solve();       --q;     }   }   