#910690 (C++17) No.2458 Line Up Charged Balls

• 問題: No.2458 Line Up Charged Balls
• ユーザー: 沙耶花
• 提出日時: 2023-09-02 21:44:08
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 145 ms / 2,000 ms
• コード長: 1,767 bytes
• コンパイル時間: 4,925 ms
• コンパイル使用メモリ: 265,084 KB
• 実行使用メモリ: 8,064 KB
• 最終ジャッジ日時: 2024-06-12 03:59:24
• 合計ジャッジ時間: 8,227 ms
• ジャッジサーバーID （参考情報）: judge2 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 5,248 KB
testcase_01	AC	3 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	2 ms; 5,376 KB
testcase_05	AC	124 ms; 8,064 KB
testcase_06	AC	126 ms; 8,064 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	131 ms; 7,424 KB
testcase_10	AC	38 ms; 5,376 KB
testcase_11	AC	3 ms; 5,376 KB
testcase_12	AC	3 ms; 5,376 KB
testcase_13	AC	73 ms; 5,760 KB
testcase_14	AC	73 ms; 5,760 KB
testcase_15	AC	34 ms; 5,376 KB
testcase_16	AC	101 ms; 8,064 KB
testcase_17	AC	109 ms; 7,976 KB
testcase_18	AC	106 ms; 8,064 KB
testcase_19	AC	129 ms; 8,064 KB
testcase_20	AC	112 ms; 8,064 KB
testcase_21	AC	102 ms; 8,064 KB
testcase_22	AC	102 ms; 8,064 KB
testcase_23	AC	139 ms; 8,064 KB
testcase_24	AC	115 ms; 7,936 KB
testcase_25	AC	145 ms; 8,064 KB
testcase_26	AC	128 ms; 8,064 KB
testcase_27	AC	145 ms; 7,936 KB

ソースコード

#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

/**
 * Author: Simon Lindholm
 * Date: 2017-04-20
 * License: CC0
 * Source: own work
 * Description: Container where you can add lines of the form kx+m, and query maximum values at points x.
 *  Useful for dynamic programming (``convex hull trick'').
 * Time: O(\log N)
 * Status: stress-tested
 */
using ll = long long;
struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k < o.k; }
	bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	ll query(ll x) {
		if(empty()){
			return -Inf64;
		}
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
};


int main(){
	
	int n;
	cin>>n;
	vector<long long> q(n);
	rep(i,n)cin>>q[i];
	
	LineContainer L;
	vector<long long> dp(n);
	rep(i,n){
		dp[i] = max(dp[i],L.query(q[i]));
		L.add(q[i],dp[i]);
	}
	long long ans = 0;
	rep(i,n)ans = max(ans,dp[i]);
	cout<<ans<<endl;
	
	return 0;
}