#1170219 (C++17) No.3579 区間積逆像

• 問題: No.3579 区間積逆像
• ユーザー: 👑 AngrySadEight
• 提出日時: 2026-07-03 21:44:32
• 言語: C++17 (gcc 15.2.0 + boost 1.89.0)
• 結果: AC
• 実行時間: 130 ms / 2,000 ms
• コード長: 4,284 bytes
• コンパイル時間: 2,919 ms
• コンパイル使用メモリ: 221,012 KB
• 実行使用メモリ: 16,768 KB
• 最終ジャッジ日時: 2026-07-03 21:45:13
• 合計ジャッジ時間: 5,776 ms
• ジャッジサーバーID （参考情報）: judge1_0 / judge2_1

ファイルパターン	結果
other	AC * 30

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;
    }
}

ll my_pow(ll x, ll n, ll mod) {
    // 　繰り返し二乗法．x^nをmodで割った余り．
    ll ret;
    if (n == 0) {
        ret = 1;
    } else if (n % 2 == 1) {
        ret = (x * my_pow((x * x) % mod, n / 2, mod)) % mod;
    } else {
        ret = my_pow((x * x) % mod, n / 2, mod);
    }
    return ret;
}

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

    // 0 でなければ逆元はある
    if (C == 0){
        vector<ll> zero_id;
        zero_id.push_back(-1);
        for (ll i = 0; i < N; i++){
            if (A[i] == 0) zero_id.push_back(i);
        }
        zero_id.push_back(N);
        ll ans = N * (N + 1) / 2;
        ll len = zero_id.size();
        for (ll i = 0; i < len - 1; i++){
            ll diffs = zero_id[i + 1] - zero_id[i];
            ans -= (diffs - 1) * diffs / 2;
        }
        cout << ans << endl;
    }
    else{
        ll inv_c = my_pow(C, P - 2, P);
        ll now_mul = 1;
        map<ll, ll> mp;
        mp[1]++;
        ll ans = 0;
        for (ll i = 0; i < N; i++){
            if (A[i] == 0){
                mp.clear();
                now_mul = 1;
                mp[now_mul]++;
            }
            else{
                now_mul = (now_mul * A[i]) % P;
                ans += mp[(now_mul * inv_c) % P];
                mp[now_mul]++;
            }
        }
        cout << ans << endl;
    }
}