結果

問題 No.1712 Read and Pile
ユーザー leaf_1415leaf_1415
提出日時 2021-10-15 23:20:45
言語 C++11
(gcc 11.4.0)
結果
AC  
実行時間 805 ms / 2,000 ms
コード長 9,593 bytes
コンパイル時間 1,225 ms
コンパイル使用メモリ 106,468 KB
実行使用メモリ 24,340 KB
最終ジャッジ日時 2024-09-17 18:14:37
合計ジャッジ時間 19,317 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge6
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 12 ms
21,748 KB
testcase_01 AC 13 ms
21,612 KB
testcase_02 AC 13 ms
21,744 KB
testcase_03 AC 12 ms
21,488 KB
testcase_04 AC 12 ms
19,508 KB
testcase_05 AC 13 ms
19,664 KB
testcase_06 AC 12 ms
19,416 KB
testcase_07 AC 13 ms
19,652 KB
testcase_08 AC 510 ms
22,128 KB
testcase_09 AC 692 ms
22,512 KB
testcase_10 AC 476 ms
22,132 KB
testcase_11 AC 558 ms
22,904 KB
testcase_12 AC 394 ms
23,796 KB
testcase_13 AC 506 ms
22,392 KB
testcase_14 AC 439 ms
22,516 KB
testcase_15 AC 594 ms
22,132 KB
testcase_16 AC 570 ms
23,028 KB
testcase_17 AC 522 ms
22,516 KB
testcase_18 AC 539 ms
22,128 KB
testcase_19 AC 496 ms
22,392 KB
testcase_20 AC 512 ms
22,388 KB
testcase_21 AC 578 ms
22,768 KB
testcase_22 AC 498 ms
22,516 KB
testcase_23 AC 667 ms
24,340 KB
testcase_24 AC 610 ms
24,176 KB
testcase_25 AC 671 ms
24,096 KB
testcase_26 AC 783 ms
24,152 KB
testcase_27 AC 805 ms
24,208 KB
testcase_28 AC 391 ms
22,772 KB
testcase_29 AC 608 ms
23,668 KB
testcase_30 AC 487 ms
23,284 KB
testcase_31 AC 240 ms
24,052 KB
testcase_32 AC 176 ms
23,536 KB
testcase_33 AC 370 ms
23,028 KB
testcase_34 AC 352 ms
23,920 KB
testcase_35 AC 534 ms
23,408 KB
testcase_36 AC 613 ms
23,848 KB
testcase_37 AC 546 ms
23,412 KB
testcase_38 AC 10 ms
21,616 KB
testcase_39 AC 18 ms
21,624 KB
testcase_40 AC 19 ms
21,624 KB
testcase_41 AC 208 ms
21,748 KB
testcase_42 AC 214 ms
21,748 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cassert>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <utility>
#include <complex>
#include <unordered_set>
#include <unordered_map>
#define rep(x, s, t) for(ll x = (s); (x) <= (t); (x)++)
#define per(x, s, t) for(ll x = (s); (x) >= (t); (x)--)
#define reps(x, s) for(ll x = 0; (x) < (ll)(s).size(); (x)++)
#define chmin(x, y) (x) = min((x), (y))
#define chmax(x, y) (x) = max((x), (y))
#define sz(x) ((ll)(x).size())
#define all(x) (x).begin(),(x).end()
#define outl(...) dump_func(__VA_ARGS__)
#define outf(x) cout << fixed << setprecision(16) << (x) << endl
#define inf 2e18
#define eps 1e-9
const double PI = 3.1415926535897932384626433;

using namespace std;

typedef long long llint;
typedef long long ll;
typedef pair<ll, ll> P;

struct edge{
	ll to, cost;
	edge(){}
	edge(ll a, ll b){ to = a, cost = b;}
};
const int dx[] = {1, 0, -1, 0}, dy[] = {0, -1, 0, 1};

//int mod = 1000000007;
int mod = 998244353;

struct mint{
	int x;
	mint(ll y = 0){if(y < 0 || y >= mod) y = (y%mod+mod)%mod; x = y;}
	mint(const mint &ope) {x = ope.x;}
	
	mint operator-(){return mint(-x);}
	mint operator+(const mint &ope){return mint(x) += ope;}
	mint operator-(const mint &ope){return mint(x) -= ope;}
	mint operator*(const mint &ope){return mint(x) *= ope;}
	mint operator/(const mint &ope){return mint(x) /= ope;}
	mint& operator+=(const mint &ope){
		x += ope.x;
		if(x >= mod) x -= mod;
		return *this;
	}
	mint& operator-=(const mint &ope){
		x += mod - ope.x;
		if(x >= mod) x -= mod;
		return *this;
	}
	mint& operator*=(const mint &ope){
		ll tmp = x;
		tmp *= ope.x, tmp %= mod;
		x = tmp;
		return *this;
	}
	mint& operator/=(const mint &ope){
		ll n = mod-2; mint mul = ope;
		while(n){
			if(n & 1) *this *= mul;
			mul *= mul;
			n >>= 1;
		}
		return *this;
	}
	mint inverse(){return mint(1) / *this;}
	bool operator ==(const mint &ope){return x == ope.x;}
	bool operator !=(const mint &ope){return x != ope.x;}
	bool operator <(const mint &ope){return x < ope.x;}
};
mint modpow(mint a, ll n){
	if(n == 0) return mint(1);
	if(n % 2) return a * modpow(a, n-1);
	else return modpow(a*a, n/2);
}
istream& operator >>(istream &is, mint &ope){
	ll t; is >> t, ope.x = t;
	return is;
}
ostream& operator <<(ostream &os, mint &ope){return os << ope.x;}
ostream& operator <<(ostream &os, const mint &ope){return os << ope.x;}

vector<mint> fact, fact_inv;
void make_fact(int n){
	fact.resize(n+1), fact_inv.resize(n+1);
	fact[0] = mint(1); rep(i, 1, n) fact[i] = fact[i-1] * mint(i);
	fact_inv[n] = fact[n].inverse(); per(i, n-1, 0) fact_inv[i] = fact_inv[i+1] * mint(i+1);
}
mint comb(int n, int k){ if(n < 0 || k < 0 || n < k) return mint(0); return fact[n] * fact_inv[k] * fact_inv[n-k];}
mint perm(int n, int k){ return comb(n, k) * fact[k]; }

vector<int> prime, pvec;
void make_prime(int n){
	prime.resize(n+1);
	rep(i, 2, n){
		if(prime[i]) continue;
		for(int j = i; j <= n; j+=i) prime[j] = i;
	}
	rep(i, 2, n) if(prime[i] == i) pvec.push_back(i);
}

bool exceed(ll x, ll y, ll m){return x >= m / y + 1;}
void mark(){ cout << "*" << endl; }
void yes(){ cout << "YES" << endl; }
void no(){ cout << "NO" << endl; }
ll floor(ll a, ll b){ if(b < 0) a *= -1, b *= -1; if(a >= 0) return a/b; else return -((-a+b-1)/b); }
ll ceil(ll a, ll b){ if(b < 0) a *= -1, b *= -1; if(a >= 0) return (a+b-1)/b; else return -((-a)/b); }
ll modulo(ll a, ll b){ b = abs(b); return a - floor(a, b) * b; }
ll sgn(ll x){ if(x > 0) return 1; if(x < 0) return -1; return 0;}
ll gcd(ll a, ll b){if(b == 0) return a; return gcd(b, a%b);}
ll lcm(ll a, ll b){return a/gcd(a, b)*b;}
ll digitnum(ll x, ll b = 10){ll ret = 0; for(; x; x /= b) ret++; return ret;}
ll digitsum(ll x, ll b = 10){ll ret = 0; for(; x; x /= b) ret += x % b; return ret;}
string lltos(ll x){string ret; for(;x;x/=10) ret += x % 10 + '0'; reverse(ret.begin(), ret.end()); return ret;}
ll stoll(string &s){ll ret = 0; for(auto c : s) ret *= 10, ret += c - '0'; return ret;}
template<typename T>
void uniq(T &vec){ sort(vec.begin(), vec.end()); vec.erase(unique(vec.begin(), vec.end()), vec.end());}

template<class S, class T> pair<S, T>& operator+=(pair<S,T> &s, const pair<S,T> &t){
	s.first += t.first, s.second += t.second;
	return s;
}
template<class S, class T> pair<S, T>& operator-=(pair<S,T> &s, const pair<S,T> &t){
	s.first -= t.first, s.second -= t.second;
	return s;
}
template<class S, class T> pair<S, T> operator+(const pair<S,T> &s, const pair<S,T> &t){
	return pair<S,T>(s.first+t.first, s.second+t.second);
}
template<class S, class T> pair<S, T> operator-(const pair<S,T> &s, const pair<S,T> &t){
	return pair<S,T>(s.first-t.first, s.second-t.second);
}
template<typename T>
ostream& operator << (ostream& os, vector<T>& vec) {
	reps(i, vec) os << vec[i] << (i + 1 == vec.size() ? "" : " "); return os;
}
template<typename T>
ostream& operator << (ostream& os, const vector<T>& vec) {
	reps(i, vec) os << vec[i] << (i + 1 == vec.size() ? "" : " "); return os;
}
template<typename T>
ostream& operator << (ostream& os, deque<T>& deq) {
	reps(i,  deq) os << deq[i] << (i + 1 == deq.size() ? "" : " "); return os;
}
template<typename T, typename U>
ostream& operator << (ostream& os, pair<T, U>& pair_var) {
	os << "(" << pair_var.first << ", " << pair_var.second << ")";
	return os;
}
template<typename T, typename U>
ostream& operator << (ostream& os, const pair<T, U>& pair_var) {
	os << "(" << pair_var.first << ", " << pair_var.second << ")";
	return os;
}
template<typename T, typename U>
ostream& operator << (ostream& os, map<T, U>& map_var) {
	for(typename map<T, U>::iterator itr = map_var.begin(); itr != map_var.end(); itr++) {
		os << "(" << itr->first << ", " << itr->second << ")";
		itr++; if(itr != map_var.end()) os << ","; itr--;
	}
	return os;
}
template<typename T>
ostream& operator << (ostream& os, set<T>& set_var) {
	for(typename set<T>::iterator itr = set_var.begin(); itr != set_var.end(); itr++) {
		os << *itr; ++itr; if(itr != set_var.end()) os << " "; itr--;
	}
	return os;
}
template<typename T>
ostream& operator << (ostream& os, multiset<T>& set_var) {
	for(typename multiset<T>::iterator itr = set_var.begin(); itr != set_var.end(); itr++) {
		os << *itr; ++itr; if(itr != set_var.end()) os << " "; itr--;
	}
	return os;
}
template<typename T>
void outa(T a[], ll s, ll t){rep(i, s, t){ cout << a[i]; if(i < t) cout << " ";}cout << endl;}
void dump_func(){cout << endl;}
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&... tail) {
	cout << head;
	if(sizeof...(Tail) > 0) cout << " ";
	dump_func(std::move(tail)...);
}


struct LazySegTree{
	typedef mint SEG;
	typedef mint DELAY;
	
	int size;
	vector<SEG> seg;
	vector<DELAY> delay;
	
	LazySegTree(){}
	LazySegTree(int size){
		this->size = size;
		seg.resize(1<<(size+1));
		delay.resize(1<<(size+1));
	}
	
	SEG Ident(){ //identity element
		return 0;
	}
	SEG ope(SEG a, SEG b){ //operator
		return a+b;
	}
	
	void init()
	{
		for(int i = 0; i < (1<<(size+1)); i++){
			seg[i] = Ident();
			delay[i] = mint(1); //
		}
	}
	
	void eval(int l, int r, int k) //
	{
		if(delay[k] != mint(1)){
			seg[k] *= delay[k];  //総和クエリのときは区間幅を乗じる必要がある
			if(l < r){
				delay[k*2] *= delay[k];
				delay[k*2+1] *= delay[k];
			}
			delay[k] = 1;
		}
	}
	
	void update(int i, SEG val)
	{
		int l = 0, r = (1<<size)-1, k = 1;
		
		eval(l, r, k);
		for(int j = size-1; j >= 0; j--){
			k <<= 1;
			if(i & (1<<j)){
				k++;
				l = (l+r)/2+1;
			}
			else r = (l+r)/2;
			eval(l, r, k);
		}
		
		seg[i+(1<<size)] = val;
		
		l = i, r = i, k = i+(1<<size);
		for(int j = 0; j < size; j++){
			k /= 2, l &= ~(1<<j), r |= 1<<j;
			eval(l, (l+r)/2, k*2), eval((l+r)/2+1, r, k*2+1);
			seg[k] = ope(seg[k*2], seg[k*2+1]);
		}
	}
	
	void add(int a, int b, int k, int l, int r, DELAY val)
	{
		eval(l, r, k);
		
		if(b < l || r < a) return;
		if(a <= l && r <= b){
			delay[k] *= val; //
			eval(l, r, k);
			return;
		}
		add(a, b, k*2, l, (l+r)/2, val);
		add(a, b, k*2+1, (l+r)/2+1, r, val);
		seg[k] = ope(seg[k*2], seg[k*2+1]);
	}
	void add(int a, int b, DELAY val){
		if(a > b) return;
		add(a, b, 1, 0, (1<<size)-1, val);
	}
 
	SEG query(int a, int b, int k, int l, int r)
	{
		eval(l, r, k);
		
		if(b < l || r < a) return Ident();
		if(a <= l && r <= b) return seg[k];
		SEG lval = query(a, b, k*2, l, (l+r)/2);
		SEG rval = query(a, b, k*2+1, (l+r)/2+1, r);
		return ope(lval, rval);
	}
	SEG query(int a, int b)
	{
		if(a > b) return Ident();
		return query(a, b, 1, 0, (1<<size)-1);
	}
};

ll n, m;
ll a[400005];
ll pre[200005];
LazySegTree seg(19), seg2(19);

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> m;
	rep(i, 1, m) cin >> a[n+i];
	rep(i, 1, n) a[i] = n+1-i, pre[n+1-i] = i;
	
	if(n == 1){
		outl(mint(m));
		return 0;
	}
	mint p = mint(n-2) / mint(n);
	
	seg.init(), seg2.init();
	rep(i, 1, n) seg.update(pre[i], 1), seg2.update(pre[i], 1);
	
	mint ans = 0, sum = n;
	rep(i, n+1, n+m){
		if(a[i] != -1){
			ll l = pre[a[i]];
			ans += seg2.query(l+1, i-1);
			ans -= seg.query(0, l-1) * seg2.query(l, l);
			//sum -= seg2.query(l, i-1);
			seg.update(l, 0), seg2.update(l, 0);
			seg.update(i, 1), seg2.update(i, 1);
			pre[a[i]] = i;
		}
		else{
			//ans += sum / n;
			//sum *= p;
			seg2.add(0, i, p);
		}
	}
	ans += mint(n-1) * mint(m);
	ans /= mint(2);
	ans += mint(m);
	
	outl(ans);
	
	return 0;
}
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