#770553 (C++14) No.5006 Hidden Maze

• 問題: No.5006 Hidden Maze
• ユーザー: square1001
• 提出日時: 2022-06-12 15:57:07
• 言語: C++14 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 89 ms / 2,000 ms
• コード長: 4,042 bytes
• コンパイル時間: 1,117 ms
• 実行使用メモリ: 22,704 KB
• スコア: 74,120
• 平均クエリ数: 259.80
• 最終ジャッジ日時: 2022-06-12 16:01:05
• 合計ジャッジ時間: 9,514 ms
• ジャッジサーバーID （参考情報）: judge13 / judge14

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	27 ms; 22,608 KB
testcase_01	AC	37 ms; 21,968 KB
testcase_02	AC	21 ms; 21,940 KB
testcase_03	AC	21 ms; 22,228 KB
testcase_04	AC	27 ms; 21,804 KB
testcase_05	AC	28 ms; 21,952 KB
testcase_06	AC	29 ms; 22,632 KB
testcase_07	AC	28 ms; 21,892 KB
testcase_08	AC	29 ms; 21,892 KB
testcase_09	AC	81 ms; 21,964 KB
testcase_10	AC	22 ms; 21,768 KB
testcase_11	AC	23 ms; 22,216 KB
testcase_12	AC	28 ms; 22,288 KB
testcase_13	AC	25 ms; 21,780 KB
testcase_14	AC	29 ms; 21,940 KB
testcase_15	AC	20 ms; 22,624 KB
testcase_16	AC	23 ms; 22,264 KB
testcase_17	AC	32 ms; 21,868 KB
testcase_18	AC	43 ms; 22,288 KB
testcase_19	AC	20 ms; 21,756 KB
testcase_20	AC	18 ms; 21,904 KB
testcase_21	AC	19 ms; 21,768 KB
testcase_22	AC	22 ms; 21,904 KB
testcase_23	AC	23 ms; 22,704 KB
testcase_24	AC	31 ms; 22,564 KB
testcase_25	AC	42 ms; 22,276 KB
testcase_26	AC	87 ms; 22,600 KB
testcase_27	AC	58 ms; 22,576 KB
testcase_28	AC	37 ms; 21,952 KB
testcase_29	AC	79 ms; 22,588 KB
testcase_30	AC	21 ms; 22,588 KB
testcase_31	AC	20 ms; 22,132 KB
testcase_32	AC	28 ms; 22,600 KB
testcase_33	AC	27 ms; 21,892 KB
testcase_34	AC	20 ms; 21,756 KB
testcase_35	AC	31 ms; 22,612 KB
testcase_36	AC	49 ms; 21,940 KB
testcase_37	AC	84 ms; 21,904 KB
testcase_38	AC	26 ms; 21,892 KB
testcase_39	AC	26 ms; 22,444 KB
testcase_40	AC	21 ms; 21,880 KB
testcase_41	AC	24 ms; 22,444 KB
testcase_42	AC	23 ms; 22,432 KB
testcase_43	AC	27 ms; 22,144 KB
testcase_44	AC	20 ms; 22,240 KB
testcase_45	AC	36 ms; 22,228 KB
testcase_46	AC	62 ms; 21,892 KB
testcase_47	AC	46 ms; 21,928 KB
testcase_48	AC	81 ms; 21,880 KB
testcase_49	AC	58 ms; 22,240 KB
testcase_50	AC	22 ms; 21,916 KB
testcase_51	AC	22 ms; 21,892 KB
testcase_52	AC	24 ms; 21,576 KB
testcase_53	AC	37 ms; 21,968 KB
testcase_54	AC	34 ms; 22,600 KB
testcase_55	AC	33 ms; 21,904 KB
testcase_56	AC	41 ms; 21,780 KB
testcase_57	AC	39 ms; 22,680 KB
testcase_58	AC	81 ms; 21,880 KB
testcase_59	AC	20 ms; 22,276 KB
testcase_60	AC	22 ms; 21,904 KB
testcase_61	AC	18 ms; 22,216 KB
testcase_62	AC	24 ms; 22,264 KB
testcase_63	AC	23 ms; 21,904 KB
testcase_64	AC	32 ms; 21,768 KB
testcase_65	AC	22 ms; 22,600 KB
testcase_66	AC	28 ms; 21,928 KB
testcase_67	AC	81 ms; 22,016 KB
testcase_68	AC	64 ms; 21,968 KB
testcase_69	AC	44 ms; 21,892 KB
testcase_70	AC	21 ms; 21,928 KB
testcase_71	AC	23 ms; 21,792 KB
testcase_72	AC	19 ms; 22,264 KB
testcase_73	AC	35 ms; 21,768 KB
testcase_74	AC	20 ms; 22,300 KB
testcase_75	AC	49 ms; 21,880 KB
testcase_76	AC	19 ms; 22,204 KB
testcase_77	AC	79 ms; 21,880 KB
testcase_78	AC	44 ms; 21,796 KB
testcase_79	AC	89 ms; 21,916 KB
testcase_80	AC	21 ms; 21,928 KB
testcase_81	AC	22 ms; 21,808 KB
testcase_82	AC	23 ms; 21,880 KB
testcase_83	AC	19 ms; 22,692 KB
testcase_84	AC	24 ms; 22,612 KB
testcase_85	AC	34 ms; 21,992 KB
testcase_86	AC	18 ms; 21,952 KB
testcase_87	AC	28 ms; 22,552 KB
testcase_88	AC	45 ms; 21,880 KB
testcase_89	AC	81 ms; 21,904 KB
testcase_90	AC	21 ms; 22,552 KB
testcase_91	AC	26 ms; 22,468 KB
testcase_92	AC	23 ms; 21,756 KB
testcase_93	AC	25 ms; 22,432 KB
testcase_94	AC	50 ms; 21,928 KB
testcase_95	AC	20 ms; 21,980 KB
testcase_96	AC	27 ms; 21,940 KB
testcase_97	AC	75 ms; 22,444 KB
testcase_98	AC	28 ms; 21,992 KB
testcase_99	AC	80 ms; 21,904 KB

ソースコード

/*
	yukicoder score contest (2022.6.12)
	author: square1001
	
	<< solution outline >>
	- repeat outputting the track with "the highest probability"
	  - probability estimation = bayesian
	  - assume that the probability to be walls are "independent"
	- highest probability track: search by dijkstra's algorithm
*/

#include <cmath>
#include <queue>
#include <string>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

uint64_t seed = 123456789ULL;
uint64_t xorshift64() {
	seed ^= seed << 13;
	seed ^= seed >> 7;
	seed ^= seed << 17;
	return seed;
}
int rand_int(int l, int r) {
	return l + int(xorshift64() % (r - l));
}
double randouble() {
	return double(xorshift64()) / double(uint64_t(-1));
}

class state {
public:
	int x, y; double prob;
	state() : x(-1), y(-1), prob(0.0) {};
	state(int x_, int y_, double prob_) : x(x_), y(y_), prob(prob_) {};
	bool operator<(const state& s) const {
		return prob < s.prob;
	}
};

int solve(int H, int W, double p) {
	// ---------- INITIAL CONFIGURATION ---------- //
	const vector<int> dx = { 1, 0, -1, 0 };
	const vector<int> dy = { 0, 1, 0, -1 };
	const string ds = "DRUL";
	const int T = 1000;
	const double wallp = 150.0 / 760.0; // (= ~19.7%)
	vector<double> wallprob(T + 1);
	for (int i = 0; i <= T; i++) {
		wallprob[i] = wallp / (wallp + (1.0 - wallp) * pow(p, i));
	}
	vector<vector<int> > wallx(H - 1, vector<int>(W, 0)); // wall between (x, y) and (x+1, y)
	vector<vector<int> > wally(H, vector<int>(W - 1, 0)); // wall between (x, y) and (x, y+1)
	
	// ---------- GAME LOOP ---------- //
	int iteration = 1;
	while (true) {
		// step #1. pre-process
		vector<vector<double> > maxprob(H, vector<double>(W, 0.0));
		maxprob[0][0] = 1.0;
		priority_queue<state> que;
		que.push(state(0, 0, 1.0));
		vector<vector<bool> > vis(H, vector<bool>(W, false));
		vector<vector<pair<int, int> > > precoord(H, vector<pair<int, int> >(W, make_pair(-1, -1)));
		while (!que.empty()) {
			state u = que.top();
			que.pop();
			if (vis[u.x][u.y]) {
				continue;
			}
			vis[u.x][u.y] = true;
			for (int i = 0; i < 4; i++) {
				int nx = u.x + dx[i], wx = (dx[i] == -1 ? u.x - 1 : u.x);
				int ny = u.y + dy[i], wy = (dy[i] == -1 ? u.y - 1 : u.y);
				if (0 <= nx && nx < H && 0 <= ny && ny < W) {
					int wallstate = (dx[i] != 0 ? wallx[wx][wy] : wally[wx][wy]);
					double nprob = u.prob * (1.0 - (wallstate == -1 ? 0.0 : wallprob[wallstate])) * (1.0 - p / 4.0);
					nprob *= 1.0 + 0.001 * min({nx, ny, H - nx - 1, W - ny - 1});
					if (maxprob[nx][ny] < nprob) {
						maxprob[nx][ny] = nprob;
						precoord[nx][ny] = make_pair(u.x, u.y);
						que.push(state(nx, ny, maxprob[nx][ny]));
					}
				}
			}
		}
		
		// step #2. calculate & output the track
		pair<int, int> cur = make_pair(H - 1, W - 1);
		string str;
		while (cur != make_pair(0, 0)) {
			pair<int, int> nxt = precoord[cur.first][cur.second];
			for (int i = 0; i < 4; i++) {
				if (nxt.first + dx[i] == cur.first && nxt.second + dy[i] == cur.second) {
					str += ds[i];
					break;
				}
			}
			cur = nxt;
		}
		reverse(str.begin(), str.end());
		cout << str << endl;
		cerr << "#" << iteration << ": prob = " << maxprob[H - 1][W - 1] << endl;
		
		// step #3. read input
		int res;
		cin >> res;
		if (res == -1) {
			return iteration;
		}
		
		// step #4. after-process
		int curx = 0, cury = 0;
		for (int i = 0; i <= res; i++) {
			int dir = ds.find(str[i]);
			int nx = curx + dx[dir], wx = (dx[dir] == -1 ? curx - 1 : curx);
			int ny = cury + dy[dir], wy = (dy[dir] == -1 ? cury - 1 : cury);
			if (dx[dir] != 0 && wallx[wx][wy] != -1) {
				wallx[wx][wy] = (i != res ? -1 : wallx[wx][wy] + 1);
			}
			if (dy[dir] != 0 && wally[wx][wy] != -1) {
				wally[wx][wy] = (i != res ? -1 : wally[wx][wy] + 1);
			}
			curx = nx;
			cury = ny;
		}
		iteration += 1;
	}
	return -1;
}

int main() {
	int H, W, PN;
	cin >> H >> W >> PN;
	int ops = solve(H, W, double(PN) / 100);
	cerr << "# of operations: " << ops << endl;
	cerr << "Score: " << (ops != -1 ? 1001 - ops : -1) << endl;
	return 0;
}