답안 #74491 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
74491	2018-09-02T13:10:44 Z	JustInCase	Mecho (IOI09_mecho)	C++17	100 / 100	306 ms	11704 KB

mecho

#include <bits/stdc++.h>
#define endl '\n'
using namespace std;

const int64_t MAX_N = 800;

const int64_t DELTA_ROWS[] = { -1, 0, 1, 0 };
const int64_t DELTA_COLS[] = { 0, 1, 0, -1 };

char board[MAX_N + 5][MAX_N + 5];
int64_t n, s, startR, startC, endR, endC, beeTimes[MAX_N + 5][MAX_N + 5];
int64_t mechoTimes[MAX_N + 5][MAX_N + 5];
vector< pair< int64_t, int64_t > > hives;

void PrecomputeBeeTimes() {
	queue< pair< int64_t, int64_t > > q;

	memset(beeTimes, -1, sizeof(beeTimes));
	for(auto &x : hives) {
		q.push(x);
		beeTimes[x.first][x.second] = 0;
	}

	while(!q.empty()) {
		int64_t r = q.front().first, c = q.front().second;
		int64_t time = beeTimes[r][c];
		q.pop();

		for(int64_t p = 0; p < 4; p++) {
			int64_t newR = r + DELTA_ROWS[p];
			int64_t newC = c + DELTA_COLS[p];

			if(newR >= 0 && newR < n && newC >= 0 && newC < n 
					&& board[newR][newC] == 'G' && beeTimes[newR][newC] == -1) {
				q.push({ newR, newC });
				beeTimes[newR][newC] = time + 1;
			}
		}
	}
}

bool Check(int64_t startTime) {
	queue< pair< int64_t, int64_t > > q;

	memset(mechoTimes, -1, sizeof(mechoTimes));
	mechoTimes[startR][startC] = startTime;
	
	if(startTime >= beeTimes[startR][startC]) {
		return false;
	}

	q.push({ startR, startC });

	while(!q.empty()) {
		int64_t r = q.front().first, c = q.front().second;
		int64_t nxtTime = mechoTimes[r][c] + 1;
		q.pop();
			
		if(r == endR && c == endC) {
			return true;
		}

		int64_t maxBeeTime;
		if(nxtTime % s == 0) {
			maxBeeTime = nxtTime + 1;
		}
		else {
			maxBeeTime = nxtTime;
		}
		
		for(int64_t p = 0; p < 4; p++) {
			int64_t newR = r + DELTA_ROWS[p];
			int64_t newC = c + DELTA_COLS[p];

			if(newR >= 0 && newR < n && newC >= 0 && newC < n 
					&& (board[newR][newC] == 'G' || board[newR][newC] == 'D')
					&& mechoTimes[newR][newC] == -1
					&& (beeTimes[newR][newC] >= maxBeeTime 
						|| beeTimes[newR][newC] < 0)) {
				q.push({ newR, newC });
				mechoTimes[newR][newC] = nxtTime;
			}
		}
	}

	return false;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);

	cin >> n >> s;

	for(int64_t i = 0; i < n; i++) {
		for(int64_t j = 0; j < n; j++) {
			cin >> board[i][j];
		
			if(board[i][j] == 'M') {
				startR = i;
				startC = j;
				board[i][j] = 'G';
			}
			else if(board[i][j] == 'D') {
				endR = i;
				endC = j;
			}
			else if(board[i][j] == 'H') {
				hives.push_back({ i, j });
			}
		}
	}

	PrecomputeBeeTimes();

	for(int64_t i = 0; i < n; i++) {
		for(int64_t j = 0; j < n; j++) {
			beeTimes[i][j] *= s;
		}	
	}

	int64_t low = 0, high = MAX_N * MAX_N * MAX_N, ans = -1;
	while(low <= high) {
		int64_t mid = (low + high) / 2;

		if(Check(mid * s)) {
			low = mid + 1;
			ans = mid;
		}
		else {
			high = mid - 1;
		}
	}

	cout << ans << endl;
}

Subtask #1
100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	18 ms	10488 KB	Output is correct
2	Correct	17 ms	10672 KB	Output is correct
3	Correct	18 ms	10672 KB	Output is correct
4	Correct	17 ms	10672 KB	Output is correct
5	Correct	19 ms	10672 KB	Output is correct
6	Correct	29 ms	10672 KB	Output is correct
7	Correct	176 ms	11704 KB	Output is correct
8	Correct	17 ms	11704 KB	Output is correct
9	Correct	18 ms	11704 KB	Output is correct
10	Correct	17 ms	11704 KB	Output is correct
11	Correct	17 ms	11704 KB	Output is correct
12	Correct	17 ms	11704 KB	Output is correct
13	Correct	18 ms	11704 KB	Output is correct
14	Correct	19 ms	11704 KB	Output is correct
15	Correct	19 ms	11704 KB	Output is correct
16	Correct	17 ms	11704 KB	Output is correct
17	Correct	18 ms	11704 KB	Output is correct
18	Correct	18 ms	11704 KB	Output is correct
19	Correct	17 ms	11704 KB	Output is correct
20	Correct	17 ms	11704 KB	Output is correct
21	Correct	37 ms	11704 KB	Output is correct
22	Correct	18 ms	11704 KB	Output is correct
23	Correct	19 ms	11704 KB	Output is correct
24	Correct	20 ms	11704 KB	Output is correct
25	Correct	17 ms	11704 KB	Output is correct
26	Correct	17 ms	11704 KB	Output is correct
27	Correct	17 ms	11704 KB	Output is correct
28	Correct	18 ms	11704 KB	Output is correct
29	Correct	18 ms	11704 KB	Output is correct
30	Correct	18 ms	11704 KB	Output is correct
31	Correct	18 ms	11704 KB	Output is correct
32	Correct	18 ms	11704 KB	Output is correct
33	Correct	30 ms	11704 KB	Output is correct
34	Correct	23 ms	11704 KB	Output is correct
35	Correct	54 ms	11704 KB	Output is correct
36	Correct	22 ms	11704 KB	Output is correct
37	Correct	22 ms	11704 KB	Output is correct
38	Correct	60 ms	11704 KB	Output is correct
39	Correct	23 ms	11704 KB	Output is correct
40	Correct	23 ms	11704 KB	Output is correct
41	Correct	80 ms	11704 KB	Output is correct
42	Correct	25 ms	11704 KB	Output is correct
43	Correct	26 ms	11704 KB	Output is correct
44	Correct	99 ms	11704 KB	Output is correct
45	Correct	27 ms	11704 KB	Output is correct
46	Correct	26 ms	11704 KB	Output is correct
47	Correct	131 ms	11704 KB	Output is correct
48	Correct	28 ms	11704 KB	Output is correct
49	Correct	30 ms	11704 KB	Output is correct
50	Correct	160 ms	11704 KB	Output is correct
51	Correct	28 ms	11704 KB	Output is correct
52	Correct	30 ms	11704 KB	Output is correct
53	Correct	185 ms	11704 KB	Output is correct
54	Correct	37 ms	11704 KB	Output is correct
55	Correct	32 ms	11704 KB	Output is correct
56	Correct	183 ms	11704 KB	Output is correct
57	Correct	31 ms	11704 KB	Output is correct
58	Correct	32 ms	11704 KB	Output is correct
59	Correct	209 ms	11704 KB	Output is correct
60	Correct	35 ms	11704 KB	Output is correct
61	Correct	33 ms	11704 KB	Output is correct
62	Correct	251 ms	11704 KB	Output is correct
63	Correct	198 ms	11704 KB	Output is correct
64	Correct	306 ms	11704 KB	Output is correct
65	Correct	298 ms	11704 KB	Output is correct
66	Correct	241 ms	11704 KB	Output is correct
67	Correct	202 ms	11704 KB	Output is correct
68	Correct	80 ms	11704 KB	Output is correct
69	Correct	83 ms	11704 KB	Output is correct
70	Correct	77 ms	11704 KB	Output is correct
71	Correct	60 ms	11704 KB	Output is correct
72	Correct	58 ms	11704 KB	Output is correct
73	Correct	82 ms	11704 KB	Output is correct
74	Correct	107 ms	11704 KB	Output is correct
75	Correct	121 ms	11704 KB	Output is correct
76	Correct	140 ms	11704 KB	Output is correct
77	Correct	124 ms	11704 KB	Output is correct
78	Correct	143 ms	11704 KB	Output is correct
79	Correct	164 ms	11704 KB	Output is correct
80	Correct	121 ms	11704 KB	Output is correct
81	Correct	147 ms	11704 KB	Output is correct
82	Correct	112 ms	11704 KB	Output is correct
83	Correct	199 ms	11704 KB	Output is correct
84	Correct	182 ms	11704 KB	Output is correct
85	Correct	120 ms	11704 KB	Output is correct
86	Correct	141 ms	11704 KB	Output is correct
87	Correct	166 ms	11704 KB	Output is correct
88	Correct	154 ms	11704 KB	Output is correct
89	Correct	188 ms	11704 KB	Output is correct
90	Correct	151 ms	11704 KB	Output is correct
91	Correct	140 ms	11704 KB	Output is correct
92	Correct	238 ms	11704 KB	Output is correct

답안 #74491

Compilation message

Subtask #1 100.0 / 100.0

Subtask #1
100.0 / 100.0