#670480 (C++14) No.1590 Random Shopping

• 問題: No.1590 Random Shopping
• ユーザー: e869120
• 提出日時: 2021-06-27 00:47:39
• 言語: C++14 (gcc 11.2.0 + boost 1.78.0)
• 結果: AC
• 実行時間: 438 ms / 5,000 ms
• コード長: 1,250 bytes
• コンパイル時間: 615 ms
• 使用メモリ: 7,684 KB
• 最終ジャッジ日時: 2023-02-01 18:19:12
• 合計ジャッジ時間: 6,367 ms
• ジャッジサーバーID （参考情報）: judge15 / judge14

入力	結果	実行時間; 使用メモリ
testcase_00	AC	2 ms; 3,548 KB
testcase_01	AC	2 ms; 3,456 KB
testcase_02	AC	2 ms; 3,524 KB
testcase_03	AC	2 ms; 3,732 KB
testcase_04	AC	1 ms; 3,524 KB
testcase_05	AC	2 ms; 3,592 KB
testcase_06	AC	2 ms; 3,544 KB
testcase_07	AC	2 ms; 3,524 KB
testcase_08	AC	2 ms; 3,576 KB
testcase_09	AC	2 ms; 3,792 KB
testcase_10	AC	4 ms; 3,884 KB
testcase_11	AC	9 ms; 4,168 KB
testcase_12	AC	32 ms; 4,856 KB
testcase_13	AC	129 ms; 5,864 KB
testcase_14	AC	418 ms; 7,532 KB
testcase_15	AC	415 ms; 7,408 KB
testcase_16	AC	415 ms; 7,528 KB
testcase_17	AC	417 ms; 7,656 KB
testcase_18	AC	1 ms; 3,520 KB
testcase_19	AC	395 ms; 7,412 KB
testcase_20	AC	1 ms; 3,728 KB
testcase_21	AC	438 ms; 7,508 KB
testcase_22	AC	2 ms; 3,660 KB
testcase_23	AC	411 ms; 7,684 KB
testcase_24	AC	410 ms; 7,412 KB
testcase_25	AC	1 ms; 3,660 KB
testcase_26	AC	1 ms; 3,728 KB
testcase_27	AC	1 ms; 3,620 KB

ソースコード

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int N, A[5009], R[5009];
int cnt[5009];
double dp[5009][5009];
vector<pair<int, int>> vec;

double solve() {
	for (int i = 0; i <= N; i++) {
		for (int j = 0; j <= N; j++) dp[i][j] = 0;
	}
	dp[0][0] = 1.0;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= N; j++) {
			dp[i + 1][j] += 0.5 * dp[i][j];
			dp[i + 1][min(j + 1, cnt[i + 1])] += 0.5 * dp[i][j];
		}
	}

	double ret = 0;
	for (int i = 1; i <= N; i++) {
		ret += 1.0 * R[i] * dp[i - 1][cnt[i]];
	}
	return ret / 2.0;
}

int main() {
	// Step #1. Input
	cin >> N;
	for (int i = 1; i <= N; i++) cin >> A[i];
	for (int i = 1; i <= N; i++) cin >> R[i];

	// Step #2. Sorting
	vec.push_back(make_pair(0, 0));
	for (int i = 1; i <= N; i++) vec.push_back(make_pair(A[i], i));
	sort(vec.begin(), vec.end());

	// Step #3. BruteForce
	double Answer = 0;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= N; j++) cnt[j] = 0;
		for (int j = 0; j <= i; j++) {
			if (vec[j].second >= 1) cnt[vec[j].second] += 1;
		}
		for (int j = 1; j <= N; j++) cnt[j] += cnt[j - 1];

		double S1 = solve();
		double S2 = 1.0 * (vec[i + 1].first - vec[i].first);
		Answer += S1 * S2;
	}
	printf("%.12lf\n", Answer);
	return 0;
}