답안 #484158

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
484158	2021-11-02T08:36:13 Z	nehasane	Mecho (IOI09_mecho)	C++14	89 / 100	659 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;
        if (max(eating_dis[startx][starty], bees_dis[startx][starty]) < eating_time && bees_visited[startx][starty])
            mecho_q.pop();
        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:75:115: warning: 'starty' may be used uninitialized in this function [-Wmaybe-uninitialized]
   75 |         if (max(eating_dis[startx][starty], bees_dis[startx][starty]) < eating_time && bees_visited[startx][starty])
      |                                                                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~^
mecho.cpp:75:115: warning: 'startx' may be used uninitialized in this function [-Wmaybe-uninitialized]
mecho.cpp:91:37: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   91 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                                     ^~
mecho.cpp:91:17: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   91 |             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	3 ms	6476 KB	Output is correct
2	Correct	3 ms	6540 KB	Output is correct
3	Correct	3 ms	6476 KB	Output is correct
4	Correct	3 ms	6600 KB	Output is correct
5	Correct	4 ms	6604 KB	Output is correct
6	Correct	4 ms	6604 KB	Output is correct
7	Correct	547 ms	10072 KB	Output is correct
8	Correct	4 ms	6604 KB	Output is correct
9	Correct	5 ms	6604 KB	Output is correct
10	Correct	4 ms	6604 KB	Output is correct
11	Correct	6 ms	6604 KB	Output is correct
12	Correct	6 ms	6732 KB	Output is correct
13	Incorrect	7 ms	6740 KB	Output isn't correct
14	Correct	10 ms	6732 KB	Output is correct
15	Correct	5 ms	6604 KB	Output is correct
16	Correct	4 ms	6604 KB	Output is correct
17	Correct	5 ms	6604 KB	Output is correct
18	Correct	5 ms	6604 KB	Output is correct
19	Correct	5 ms	6604 KB	Output is correct
20	Correct	7 ms	6604 KB	Output is correct
21	Correct	6 ms	6604 KB	Output is correct
22	Correct	5 ms	6704 KB	Output is correct
23	Correct	6 ms	6732 KB	Output is correct
24	Correct	7 ms	6732 KB	Output is correct
25	Correct	6 ms	6732 KB	Output is correct
26	Correct	6 ms	6776 KB	Output is correct
27	Correct	9 ms	6732 KB	Output is correct
28	Correct	10 ms	6732 KB	Output is correct
29	Correct	7 ms	6732 KB	Output is correct
30	Correct	8 ms	6732 KB	Output is correct
31	Correct	7 ms	6732 KB	Output is correct
32	Correct	9 ms	6732 KB	Output is correct
33	Correct	44 ms	7796 KB	Output is correct
34	Correct	41 ms	7740 KB	Output is correct
35	Correct	82 ms	7836 KB	Output is correct
36	Correct	54 ms	8012 KB	Output is correct
37	Correct	56 ms	8012 KB	Output is correct
38	Correct	102 ms	8020 KB	Output is correct
39	Correct	87 ms	8144 KB	Output is correct
40	Correct	75 ms	8116 KB	Output is correct
41	Correct	126 ms	8140 KB	Output is correct
42	Correct	83 ms	8604 KB	Output is correct
43	Correct	78 ms	8604 KB	Output is correct
44	Correct	165 ms	8620 KB	Output is correct
45	Correct	97 ms	8780 KB	Output is correct
46	Correct	90 ms	8812 KB	Output is correct
47	Correct	203 ms	8816 KB	Output is correct
48	Correct	109 ms	8908 KB	Output is correct
49	Correct	109 ms	9016 KB	Output is correct
50	Correct	228 ms	8908 KB	Output is correct
51	Correct	138 ms	9284 KB	Output is correct
52	Correct	128 ms	9220 KB	Output is correct
53	Correct	285 ms	9232 KB	Output is correct
54	Correct	155 ms	9412 KB	Output is correct
55	Correct	162 ms	9432 KB	Output is correct
56	Correct	354 ms	9448 KB	Output is correct
57	Correct	170 ms	9544 KB	Output is correct
58	Correct	170 ms	9672 KB	Output is correct
59	Correct	378 ms	9644 KB	Output is correct
60	Correct	195 ms	9836 KB	Output is correct
61	Correct	186 ms	9924 KB	Output is correct
62	Correct	422 ms	9804 KB	Output is correct
63	Correct	504 ms	9972 KB	Output is correct
64	Correct	623 ms	9840 KB	Output is correct
65	Correct	659 ms	9848 KB	Output is correct
66	Correct	556 ms	9836 KB	Output is correct
67	Correct	559 ms	9924 KB	Output is correct
68	Correct	483 ms	9872 KB	Output is correct
69	Correct	520 ms	9920 KB	Output is correct
70	Correct	455 ms	9888 KB	Output is correct
71	Correct	487 ms	9988 KB	Output is correct
72	Incorrect	466 ms	9924 KB	Output isn't correct
73	Incorrect	440 ms	10052 KB	Output isn't correct
74	Correct	468 ms	10232 KB	Output is correct
75	Correct	532 ms	10060 KB	Output is correct
76	Correct	482 ms	10180 KB	Output is correct
77	Correct	474 ms	10180 KB	Output is correct
78	Correct	506 ms	10052 KB	Output is correct
79	Correct	478 ms	10100 KB	Output is correct
80	Correct	468 ms	10060 KB	Output is correct
81	Correct	503 ms	9992 KB	Output is correct
82	Correct	521 ms	10064 KB	Output is correct
83	Correct	642 ms	9984 KB	Output is correct
84	Correct	532 ms	10064 KB	Output is correct
85	Correct	545 ms	10064 KB	Output is correct
86	Correct	491 ms	10052 KB	Output is correct
87	Correct	506 ms	10156 KB	Output is correct
88	Correct	513 ms	10008 KB	Output is correct
89	Correct	514 ms	10000 KB	Output is correct
90	Correct	504 ms	9892 KB	Output is correct
91	Correct	497 ms	9932 KB	Output is correct
92	Correct	540 ms	10016 KB	Output is correct