답안 #484153

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
484153	2021-11-02T08:16:29 Z	nehasane	Mecho (IOI09_mecho)	C++14	89 / 100	617 ms	10232 KB

mecho

#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 800;
vector <string> field(MAX_N);
bool bees_visited[MAX_N][MAX_N], mecho_visited[MAX_N][MAX_N];
int mecho_dis[MAX_N][MAX_N], bees_dis[MAX_N][MAX_N], eating_dis[MAX_N][MAX_N];
queue <pair <int, int>> mecho_q, bees_q;
int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};
int n, s;
bool valid_sq(int x, int y, bool is_mecho){
    if (x >= 0 && x < n && y >= 0 && y < n){
        if (is_mecho && (field[x][y] == 'G' || field[x][y] == 'D' || field[x][y] == 'M'))
            return true;
        else if (!is_mecho && (field[x][y] == 'G' || field[x][y] == 'M'))
            return true;
        return false;
    }
    return false;
}
int main()
{
    // freopen("in.txt", "r", stdin);
    // freopen("out.txt", "w", stdout);
    cin >> n >> s;
    for (int i = 0; i < n; i++)
        cin >> field[i];
    vector <pair <int, int>> hives;
    int startx, starty, home_x, home_y;
    //find Mecho's position
    for (int i = 0; i < n; i++){
        for (int j = 0; j < n; j++){
            if (field[i][j] == 'M'){
                startx = i;
                starty = j;
            }else if (field[i][j] == 'H'){
                hives.push_back({i, j});
            }else if (field[i][j] == 'D'){
                home_x = i;
                home_y = j;
            }
        }
    }
    int l = 0, r = n*n;
    while (l <= r){
        int eating_time = (l + r) / 2;
        memset(bees_visited, false, sizeof(bees_visited));
        memset(mecho_visited, false, sizeof(mecho_visited));
        memset(bees_dis, 0, sizeof(bees_dis));
        memset(mecho_dis, 0, sizeof(mecho_dis));
        //move bees
        for (auto i : hives){
            bees_q.push({i.first, i.second});
            bees_visited[i.first][i.second] = true;
        }
        while (!bees_q.empty()){
            int x = bees_q.front().first, y = bees_q.front().second;
            bees_q.pop();
            for (int i = 0; i < 4; i++){
                int nx = x + dx[i], ny = y + dy[i];
                if (valid_sq(nx, ny, false) && !bees_visited[nx][ny]){
                    if (eating_dis[x][y] < eating_time){
                        eating_dis[nx][ny] = eating_dis[x][y] + 1;
                    }else{
                        bees_dis[nx][ny] = bees_dis[x][y] + 1;
                        eating_dis[nx][ny] = INT_MAX;
                    }
                    bees_q.push({nx, ny});
                    bees_visited[nx][ny] = true;
                }
            }
        }
        mecho_q.push({startx, starty});
        mecho_visited[startx][starty] = true;
        while (!mecho_q.empty()){
            int x = mecho_q.front().first, y = mecho_q.front().second;
            mecho_q.pop();
            for (int i = 0; i < 4; i++){
                int nx = x + dx[i], ny = y + dy[i];
                if (valid_sq(nx, ny, true) && !mecho_visited[nx][ny] && (mecho_dis[x][y] + 1) / s < bees_dis[nx][ny]){
                    mecho_visited[nx][ny] = true;
                    mecho_q.push({nx, ny});
                    mecho_dis[nx][ny] = mecho_dis[x][y] + 1;
                }
            }
        }
        bool mecho_reached = false;
        for (int i = 0; i < 4; i++){
            int nx = home_x+ dx[i], ny = home_y + dy[i];
            if (valid_sq(nx, ny, true)){
                if (bees_dis[nx][ny] > (mecho_dis[nx][ny] / s) && mecho_visited[nx][ny]){
                    mecho_reached = true;
                    break;
                }
            }
        }
        if (mecho_reached)
            l = eating_time + 1;
        else
            r = eating_time - 1;
        }
    cout << l - 1 << '\n';
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:74:39: warning: 'starty' may be used uninitialized in this function [-Wmaybe-uninitialized]
   74 |         mecho_visited[startx][starty] = true;
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
mecho.cpp:74:39: warning: 'startx' may be used uninitialized in this function [-Wmaybe-uninitialized]
mecho.cpp:89:37: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   89 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                                     ^~
mecho.cpp:89:17: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   89 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                 ^~

Subtask #1

89.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	4 ms	6476 KB	Output is correct
2	Correct	4 ms	6604 KB	Output is correct
3	Correct	3 ms	6476 KB	Output is correct
4	Correct	5 ms	6604 KB	Output is correct
5	Correct	4 ms	6604 KB	Output is correct
6	Correct	4 ms	6604 KB	Output is correct
7	Correct	502 ms	9920 KB	Output is correct
8	Correct	4 ms	6604 KB	Output is correct
9	Correct	5 ms	6604 KB	Output is correct
10	Correct	5 ms	6604 KB	Output is correct
11	Correct	4 ms	6604 KB	Output is correct
12	Correct	6 ms	6732 KB	Output is correct
13	Incorrect	7 ms	6744 KB	Output isn't correct
14	Correct	8 ms	6780 KB	Output is correct
15	Correct	5 ms	6604 KB	Output is correct
16	Correct	5 ms	6604 KB	Output is correct
17	Correct	6 ms	6732 KB	Output is correct
18	Correct	5 ms	6604 KB	Output is correct
19	Correct	5 ms	6604 KB	Output is correct
20	Correct	5 ms	6604 KB	Output is correct
21	Correct	5 ms	6604 KB	Output is correct
22	Correct	6 ms	6604 KB	Output is correct
23	Correct	5 ms	6732 KB	Output is correct
24	Correct	5 ms	6732 KB	Output is correct
25	Correct	5 ms	6732 KB	Output is correct
26	Correct	8 ms	6860 KB	Output is correct
27	Correct	7 ms	6732 KB	Output is correct
28	Correct	8 ms	6732 KB	Output is correct
29	Correct	8 ms	6732 KB	Output is correct
30	Correct	7 ms	6732 KB	Output is correct
31	Correct	6 ms	6828 KB	Output is correct
32	Correct	7 ms	6732 KB	Output is correct
33	Correct	45 ms	7756 KB	Output is correct
34	Correct	39 ms	7756 KB	Output is correct
35	Correct	90 ms	7868 KB	Output is correct
36	Correct	50 ms	8012 KB	Output is correct
37	Correct	51 ms	8004 KB	Output is correct
38	Correct	95 ms	8012 KB	Output is correct
39	Correct	62 ms	8188 KB	Output is correct
40	Correct	67 ms	8192 KB	Output is correct
41	Correct	132 ms	8212 KB	Output is correct
42	Correct	77 ms	8524 KB	Output is correct
43	Correct	92 ms	8536 KB	Output is correct
44	Correct	157 ms	8560 KB	Output is correct
45	Correct	101 ms	8780 KB	Output is correct
46	Correct	92 ms	8900 KB	Output is correct
47	Correct	184 ms	8824 KB	Output is correct
48	Correct	107 ms	9092 KB	Output is correct
49	Correct	108 ms	9036 KB	Output is correct
50	Correct	238 ms	9152 KB	Output is correct
51	Correct	131 ms	9204 KB	Output is correct
52	Correct	129 ms	9164 KB	Output is correct
53	Correct	288 ms	9236 KB	Output is correct
54	Correct	175 ms	9420 KB	Output is correct
55	Correct	151 ms	9328 KB	Output is correct
56	Correct	337 ms	9420 KB	Output is correct
57	Correct	172 ms	9640 KB	Output is correct
58	Correct	165 ms	9548 KB	Output is correct
59	Correct	384 ms	9640 KB	Output is correct
60	Correct	200 ms	9804 KB	Output is correct
61	Correct	187 ms	9752 KB	Output is correct
62	Correct	450 ms	9856 KB	Output is correct
63	Correct	496 ms	9804 KB	Output is correct
64	Correct	617 ms	9924 KB	Output is correct
65	Correct	556 ms	9844 KB	Output is correct
66	Correct	521 ms	9804 KB	Output is correct
67	Correct	509 ms	9848 KB	Output is correct
68	Correct	477 ms	9804 KB	Output is correct
69	Correct	492 ms	9924 KB	Output is correct
70	Correct	489 ms	9936 KB	Output is correct
71	Correct	492 ms	9876 KB	Output is correct
72	Incorrect	471 ms	9872 KB	Output isn't correct
73	Incorrect	453 ms	10148 KB	Output isn't correct
74	Correct	466 ms	10180 KB	Output is correct
75	Correct	539 ms	10232 KB	Output is correct
76	Correct	486 ms	10136 KB	Output is correct
77	Correct	482 ms	10188 KB	Output is correct
78	Correct	501 ms	10176 KB	Output is correct
79	Correct	483 ms	10100 KB	Output is correct
80	Correct	482 ms	10040 KB	Output is correct
81	Correct	494 ms	10100 KB	Output is correct
82	Correct	542 ms	10112 KB	Output is correct
83	Correct	510 ms	10180 KB	Output is correct
84	Correct	481 ms	10068 KB	Output is correct
85	Correct	536 ms	10052 KB	Output is correct
86	Correct	499 ms	10060 KB	Output is correct
87	Correct	496 ms	10180 KB	Output is correct
88	Correct	505 ms	10052 KB	Output is correct
89	Correct	491 ms	9932 KB	Output is correct
90	Correct	508 ms	10000 KB	Output is correct
91	Correct	499 ms	9932 KB	Output is correct
92	Correct	529 ms	10004 KB	Output is correct