結果

問題 No.2950 Max Min Product
コンテスト
ユーザー 👑 binap
提出日時 2024-10-25 23:33:36
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 4,354 bytes
コンパイル時間 4,462 ms
コンパイル使用メモリ 256,260 KB
最終ジャッジ日時 2025-02-24 23:55:33
ジャッジサーバーID
（参考情報） 		judge2 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 1 WA * 2
other WA * 1 OLE * 36
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<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<vector<int>> vvi;
typedef vector<vector<long long>> vvl;
typedef long double ld;
typedef pair<int, int> P;

template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;}
template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;}
template <int m> istream& operator>>(istream& is, static_modint<m>& a) {long long x; is >> x; a = x; return is;}
template <int m> istream& operator>>(istream& is, dynamic_modint<m>& a) {long long x; is >> x; a = x; return is;}
template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;}
template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;}
template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}
template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}

template<typename T> void chmin(T& a, T b){a = min(a, b);}
template<typename T> void chmax(T& a, T b){a = max(a, b);}

using mint = modint998244353;
int main(){
	int n;
	cin >> n;
	vector<int> a(n);
	cin >> a;
	
	mint ans = 0;
	
	auto dfs = [&](auto self, int left, int right) -> void {
		if(right == left + 1){
			ans += mint(a[left]) * a[left];
			return;
		}
		int mid = (right + left) / 2;
		self(self, left, mid);
		self(self, mid, right);
		
		int ln = mid - left;
		int rn = right - mid;
		vector<int> lmax(ln);
		vector<int> lmin(ln);
		vector<int> rmax(rn);
		vector<int> rmin(rn);
		{
			int tmp = 0;
			rep(i, ln){
				int idx = (mid - 1) - i;
				chmax(tmp, a[idx]);
				lmax[i] = tmp;
			}
		}
		{
			int tmp = 1001001001;
			rep(i, ln){
				int idx = (mid - 1) - i;
				chmin(tmp, a[idx]);
				lmin[i] = tmp;
			}
		}
		{
			int tmp = 0;
			rep(i, rn){
				int idx = mid + i;
				chmax(tmp, a[idx]);
				rmax[i] = tmp;
			}
		}
		{
			int tmp = 1001001001;
			rep(i, rn){
				int idx = mid + i;
				chmin(tmp, a[idx]);
				rmin[i] = tmp;
			}
		}
		
		vector<mint> lmax_sum(ln + 1);
		vector<mint> rmax_sum(rn + 1);
		
		rep(li, ln) lmax_sum[li + 1] = lmax_sum[li] + lmax[li];
		rep(ri, rn)	rmax_sum[ri + 1] = rmax_sum[ri] + rmax[ri];
		
		cout << lmax;
		cout << lmin;
		cout << rmax;
		cout << rmin;
		
		int li = 0;
		int ri = 0;
		
		mint plus = 0;
		
		auto right_up = [&](){
			int idx = upper_bound(lmax.begin(), lmax.end(), rmax[ri]) - lmax.begin();
			if(idx < li) plus += (mint)(rmax[ri] * idx + (lmax_sum[li] - lmax_sum[idx])) * rmin[ri];
			else plus += (mint)(rmax[ri] * li) * rmin[ri];
			ri++;
		};
		auto left_up = [&](){
			int idx = upper_bound(rmax.begin(), rmax.end(), lmax[li]) - rmax.begin();
			if(idx < ri) plus += (mint)(lmax[li] * idx + (rmax_sum[ri] - rmax_sum[idx])) * lmin[li];
			else plus += (mint)(lmax[li] * ri) * lmin[li];
			li++;
		};
		
		while(li < ln or ri < rn){
			if(li == ln){
				right_up();
				continue;
			}
			if(ri == rn){
				left_up();
				continue;
			}
			if(lmin[li] < rmin[ri]){
				right_up();
			}else{
				left_up();
			}
		}
		
		ans += plus;
		cout << plus << "\n";
		
	};
	dfs(dfs, 0, n);
	
	cout << ans << "\n";
	return 0;
}
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