#1177732 (C++17) No.1526 Sum of Mex 2

• 問題: No.1526 Sum of Mex 2
• ユーザー: 👑 AngrySadEight
• 提出日時: 2026-08-20 01:52:24
• 言語: C++17 (gcc 15.2.0 + boost 1.90.0)
• 結果: AC
• 実行時間: 81 ms / 3,000 ms
• コード長: 4,480 bytes
• コンパイル時間: 2,827 ms
• コンパイル使用メモリ: 222,340 KB
• 実行使用メモリ: 13,804 KB
• 最終ジャッジ日時: 2026-08-20 01:52:51
• 合計ジャッジ時間: 5,712 ms
• ジャッジサーバーID （参考情報）: judge1_1 / judge2_0

ファイルパターン	結果
sample	AC * 3
other	AC * 32

ソースコード

#include <algorithm>
#include <atcoder/all>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define mod1 1000000007
#define mod2 998244353
#define mod3 100000007
#define vi vector<int>
#define vs vector<string>
#define vc vector<char>
#define vl vector<ll>
#define vb vector<bool>
#define vvi vector<vector<int>>
#define vvc vector<vector<char>>
#define vvl vector<vector<ll>>
#define vvb vector<vector<bool>>
#define vvvi vector<vector<vector<int>>>
#define vvvl vector<vector<vector<ll>>>
#define pii pair<int, int>
#define pil pair<int, ll>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define vpii vector<pair<int, int>>
#define vpll vector<pair<ll, ll>>
#define vvpii vector<vector<pair<int, int>>>
#define vvpll vector<vector<pair<ll, ll>>>

template <typename T>
void debug(T e) {
    cerr << e << endl;
}

template <typename T>
void debug(vector<T> &v) {
    rep(i, v.size()) { cerr << v[i] << " "; }
    cerr << endl;
}

template <typename T>
void debug(vector<vector<T>> &v) {
    rep(i, v.size()) {
        rep(j, v[i].size()) { cerr << v[i][j] << " "; }
        cerr << endl;
    }
}

template <typename T>
void debug(vector<pair<T, T>> &v) {
    rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; }
}

template <typename T>
void debug(set<T> &st) {
    for (auto itr = st.begin(); itr != st.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(multiset<T> &ms) {
    for (auto itr = ms.begin(); itr != ms.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(map<T, T> &mp) {
    for (auto itr = mp.begin(); itr != mp.end(); itr++) {
        cerr << itr->first << " " << itr->second << endl;
    }
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << H << " ";
    debug_out(T...);
}

using mint = modint998244353;

void debug_mint1(vector<mint> &vec) {
    for (int i = 0; i < vec.size(); i++) {
        cerr << vec[i].val() << " ";
    }
    cerr << endl;
}

void debug_mint2(vector<vector<mint>> &vec) {
    for (int i = 0; i < vec.size(); i++) {
        for (int j = 0; j < vec[i].size(); j++) {
            cerr << vec[i][j].val() << " ";
        }
        cerr << endl;
    }
}

// 区間更新区間和の遅延セグ木

struct S{
    ll val;
    ll size;
};

S op(S a, S b){
    return S{a.val + b.val, a.size + b.size};
}

S e(){
    return S{0, 0};
}

ll ID = 1000000000002LL;

S mapping(ll f, S x){
    if (f == ID) return x;
    x.val = f * x.size;
    return x;
}

ll composition(ll f, ll g){
    if (f == ID) return g;
    return f;
}

ll id(){
    return ID;
}

int main() {
    ll N;
    cin >> N;
    vector<ll> A(N);
    rep(i, N){
        cin >> A[i];
        A[i]--;
    }

    // 遅延セグ木
    lazy_segtree<S, op, e, ll, mapping, composition, id> seg(N + 1);
    rep(i, N){
        seg.set(i, S{-1, 1});
    }
    vector<vector<ll>> ids(N + 1, vector<ll>(0));
    rep(i, N){
        ids[A[i]].push_back(i);
    }
    ll ans = 0;
    for (ll i = 0; i < N; i++){
        for (ll j = 0; j < ids[i].size(); j++){
            ll left;
            if (j == 0) left = 0;
            else left = ids[i][j - 1] + 1;
            ll start = left;
            ll right = ids[i][j] + 1;
            if (seg.get(left).val > ids[i][j]) continue;
            while (right - left > 1){
                ll mid = (left + right) / 2;
                if (seg.get(mid).val > ids[i][j]){
                    right = mid;
                }
                else{
                    left = mid;
                }
            }
            seg.apply(start, right, ids[i][j]);
        }
        if (ids[i].size() == 0){
            break;
        }
        seg.apply(ids[i][ids[i].size() - 1] + 1, N, N);
        ans += (N * N - seg.prod(0, N).val);
    }
    cout << ans + (N * (N + 1) / 2) << endl;
}