Submission #550471

# Submission time Handle Problem Language Result Execution time Memory
550471 2022-04-18T09:10:02 Z Jomnoi Mecho (IOI09_mecho) C++17
84 / 100
166 ms 6560 KB
#include <bits/stdc++.h>
#define DEBUG false
using namespace std;

const int MAX_N = 810;
const int INF = 1e9 + 7;
const int d[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};

char s[MAX_N][MAX_N];
int db[MAX_N][MAX_N], dm[MAX_N][MAX_N];

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int N, S;
    cin >> N >> S;
    for(int i = 1; i <= N; i++) {
        cin >> (s[i] + 1);
    }

    int sx, sy, ex, ey;
    queue <pair <int, int>> q;
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= N; j++) {
            db[i][j] = INF;
            if(s[i][j] == 'H') {
                db[i][j] = 0;
                q.emplace(i, j);
            }
            else if(s[i][j] == 'M') {
                sx = i, sy = j;
            }
            else if(s[i][j] == 'D') {
                ex = i, ey = j;
            }
        }    
    }
    while(!q.empty()) {
        auto [ux, uy] = q.front();
        q.pop();

        for(int i = 0; i < 4; i++) {
            int vx = ux + d[i][0], vy = uy + d[i][1];
            if(vx < 1 or vx > N or vy < 1 or vy > N or s[vx][vy] == 'T' or s[vx][vy] == 'D' or db[vx][vy] != INF) {
                continue;
            }

            db[vx][vy] = db[ux][uy] + 1;
            q.emplace(vx, vy);
        }
    }

    int l = 0, r = 1e9, ans = -1;
    while(l <= r) {
        int mid = (l + r) / 2;

        for(int i = 1; i <= N; i++) {
            for(int j = 1; j <= N; j++) {
                dm[i][j] = INF;
            }
        }

        queue <pair <int, int>> q;
        q.emplace(sx, sy);
        dm[sx][sy] = 0;
        while(!q.empty()) {
            auto [ux, uy] = q.front();
            q.pop();

            for(int i = 0; i < 4; i++) {
                int vx = ux + d[i][0], vy = uy + d[i][1];
                if(vx < 1 or vx > N or vy < 1 or vy > N or s[vx][vy] == 'T' or dm[vx][vy] != INF) {
                    continue;
                }
                if((dm[ux][uy] + 1) / S >= db[vx][vy] - mid) {
                    continue;
                }

                dm[vx][vy] = dm[ux][uy] + 1;
                q.emplace(vx, vy);
            }
        }

        if(dm[ex][ey] == INF) {
            r = mid - 1;
        }
        else {
            l = mid + 1;
            ans = mid;
        }
    }
    cout << ans;
    return 0;
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:83:21: warning: 'ey' may be used uninitialized in this function [-Wmaybe-uninitialized]
   83 |         if(dm[ex][ey] == INF) {
      |            ~~~~~~~~~^
mecho.cpp:83:21: warning: 'ex' may be used uninitialized in this function [-Wmaybe-uninitialized]
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 324 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 324 KB Output is correct
7 Correct 110 ms 6388 KB Output is correct
8 Correct 1 ms 324 KB Output is correct
9 Correct 1 ms 328 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 336 KB Output is correct
12 Incorrect 1 ms 724 KB Output isn't correct
13 Incorrect 1 ms 596 KB Output isn't correct
14 Correct 1 ms 724 KB Output is correct
15 Correct 1 ms 452 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 1 ms 468 KB Output is correct
20 Correct 1 ms 456 KB Output is correct
21 Correct 1 ms 596 KB Output is correct
22 Correct 1 ms 596 KB Output is correct
23 Correct 1 ms 592 KB Output is correct
24 Correct 1 ms 580 KB Output is correct
25 Correct 1 ms 724 KB Output is correct
26 Correct 1 ms 724 KB Output is correct
27 Correct 1 ms 724 KB Output is correct
28 Correct 1 ms 720 KB Output is correct
29 Correct 1 ms 724 KB Output is correct
30 Correct 1 ms 724 KB Output is correct
31 Correct 1 ms 852 KB Output is correct
32 Correct 1 ms 852 KB Output is correct
33 Correct 6 ms 2892 KB Output is correct
34 Correct 7 ms 2888 KB Output is correct
35 Correct 30 ms 2900 KB Output is correct
36 Correct 7 ms 3284 KB Output is correct
37 Correct 8 ms 3284 KB Output is correct
38 Correct 31 ms 3284 KB Output is correct
39 Correct 9 ms 3668 KB Output is correct
40 Correct 8 ms 3668 KB Output is correct
41 Correct 36 ms 3728 KB Output is correct
42 Correct 9 ms 4040 KB Output is correct
43 Correct 9 ms 4052 KB Output is correct
44 Correct 48 ms 4128 KB Output is correct
45 Correct 14 ms 4488 KB Output is correct
46 Correct 12 ms 4436 KB Output is correct
47 Correct 59 ms 4440 KB Output is correct
48 Correct 13 ms 4816 KB Output is correct
49 Correct 13 ms 4864 KB Output is correct
50 Correct 63 ms 4864 KB Output is correct
51 Correct 15 ms 5144 KB Output is correct
52 Correct 16 ms 5220 KB Output is correct
53 Correct 74 ms 5220 KB Output is correct
54 Correct 18 ms 5460 KB Output is correct
55 Correct 24 ms 5576 KB Output is correct
56 Correct 97 ms 5568 KB Output is correct
57 Correct 17 ms 5876 KB Output is correct
58 Correct 18 ms 5844 KB Output is correct
59 Correct 100 ms 5996 KB Output is correct
60 Correct 20 ms 6184 KB Output is correct
61 Correct 30 ms 6216 KB Output is correct
62 Correct 115 ms 6228 KB Output is correct
63 Correct 112 ms 6284 KB Output is correct
64 Correct 166 ms 6212 KB Output is correct
65 Correct 157 ms 6220 KB Output is correct
66 Correct 116 ms 6192 KB Output is correct
67 Correct 122 ms 6284 KB Output is correct
68 Correct 47 ms 6204 KB Output is correct
69 Correct 47 ms 6204 KB Output is correct
70 Correct 32 ms 6220 KB Output is correct
71 Correct 42 ms 6304 KB Output is correct
72 Incorrect 32 ms 6220 KB Output isn't correct
73 Incorrect 43 ms 6472 KB Output isn't correct
74 Correct 63 ms 6560 KB Output is correct
75 Correct 63 ms 6552 KB Output is correct
76 Correct 65 ms 6560 KB Output is correct
77 Correct 60 ms 6464 KB Output is correct
78 Correct 74 ms 6444 KB Output is correct
79 Correct 60 ms 6532 KB Output is correct
80 Correct 61 ms 6556 KB Output is correct
81 Correct 68 ms 6528 KB Output is correct
82 Correct 57 ms 6536 KB Output is correct
83 Correct 79 ms 6496 KB Output is correct
84 Correct 71 ms 6388 KB Output is correct
85 Correct 66 ms 6440 KB Output is correct
86 Correct 74 ms 6480 KB Output is correct
87 Correct 72 ms 6484 KB Output is correct
88 Correct 82 ms 6336 KB Output is correct
89 Correct 85 ms 6348 KB Output is correct
90 Correct 79 ms 6440 KB Output is correct
91 Correct 78 ms 6440 KB Output is correct
92 Correct 87 ms 6352 KB Output is correct