Submission #109011

# Submission time Handle Problem Language Result Execution time Memory
109011 2019-05-04T01:53:50 Z PeppaPig Mecho (IOI09_mecho) C++14
100 / 100
272 ms 6940 KB
#include <bits/stdc++.h>

#define pii pair<int, int>
#define x first
#define y second

using namespace std;

const int N = 805;
const int dx[4] = {0, 1, 0, -1};
const int dy[4] = {1, 0, -1, 0};

int n, s;
int sx, sy, bee[N][N], d[N][N];
char A[N][N];

void gen_bee() {
    queue<pii> Q;
    for(int i = 1; i <= n; i++) for(int j = 1; j <= n; j++) {
        if(A[i][j] == 'M') sx = i, sy = j;
        if(A[i][j] == 'H') {
            bee[i][j] = 0;
            Q.emplace(i, j);
        }
    }
    while(!Q.empty()) {
        pii u = Q.front(); Q.pop();
        for(int i = 0; i < 4; i++) {
            int nr = u.x + dx[i], nc = u.y + dy[i];
            if(nr < 1 || nr > n || nc < 1 || nc > n) continue;
            if(A[nr][nc] != 'G' && A[nr][nc] != 'M') continue;
            if(bee[u.x][u.y] + 1 < bee[nr][nc]) {
                bee[nr][nc] = bee[u.x][u.y] + 1;
                Q.emplace(nr, nc);
            }
        }
    }
}

bool chk(int mid) {
    if(1ll * mid >= bee[sx][sy]) return false;
    fill_n(d[0], N*N, 1e9+1);
    queue<pii> Q;
    d[sx][sy] = 0;
    Q.emplace(sx, sy);
    while(!Q.empty()) {
        pii u = Q.front(); Q.pop();
        if(A[u.x][u.y] == 'D') return true;
        for(int i = 0; i < 4; i++) {
            int nr = u.x + dx[i], nc = u.y + dy[i];
            if(nr < 1 || nr > n || nc < 1 || nc > n) continue;
            if(A[nr][nc] != 'M' && A[nr][nc] != 'G' && A[nr][nc] != 'D') continue;
            if(d[u.x][u.y] + 1 < d[nr][nc] && 1ll * d[u.x][u.y] + 1 < 1ll * s * (bee[nr][nc] - mid)) {
                d[nr][nc] = d[u.x][u.y] + 1;
                Q.emplace(nr, nc);
            } 
        }
    }
    return false;
}

int main() {
    fill_n(bee[0], N*N, 1e9+1);
    scanf("%d %d", &n, &s);
    for(int i = 1; i <= n; i++) scanf(" %s", A[i] + 1);
    gen_bee();

    int l = 0, r = n * n;
    while(l < r) {
        int mid = (l + r + 1) >> 1;
        if(chk(mid)) l = mid;
        else r = mid-1;
    }
    if(chk(l)) printf("%d\n", l);
    else printf("-1\n");

    return 0;
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:64:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &s);
     ~~~~~^~~~~~~~~~~~~~~~~
mecho.cpp:65:38: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i = 1; i <= n; i++) scanf(" %s", A[i] + 1);
                                 ~~~~~^~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 7 ms 5376 KB Output is correct
2 Correct 8 ms 5376 KB Output is correct
3 Correct 8 ms 5376 KB Output is correct
4 Correct 7 ms 5372 KB Output is correct
5 Correct 6 ms 5376 KB Output is correct
6 Correct 8 ms 5376 KB Output is correct
7 Correct 129 ms 6784 KB Output is correct
8 Correct 8 ms 5376 KB Output is correct
9 Correct 9 ms 5376 KB Output is correct
10 Correct 10 ms 5376 KB Output is correct
11 Correct 9 ms 5504 KB Output is correct
12 Correct 9 ms 5504 KB Output is correct
13 Correct 8 ms 5376 KB Output is correct
14 Correct 10 ms 5504 KB Output is correct
15 Correct 11 ms 5376 KB Output is correct
16 Correct 9 ms 5376 KB Output is correct
17 Correct 12 ms 5504 KB Output is correct
18 Correct 9 ms 5348 KB Output is correct
19 Correct 11 ms 5376 KB Output is correct
20 Correct 10 ms 5376 KB Output is correct
21 Correct 10 ms 5504 KB Output is correct
22 Correct 11 ms 5504 KB Output is correct
23 Correct 9 ms 5504 KB Output is correct
24 Correct 8 ms 5504 KB Output is correct
25 Correct 9 ms 5504 KB Output is correct
26 Correct 9 ms 5376 KB Output is correct
27 Correct 9 ms 5504 KB Output is correct
28 Correct 11 ms 5504 KB Output is correct
29 Correct 13 ms 5504 KB Output is correct
30 Correct 10 ms 5504 KB Output is correct
31 Correct 11 ms 5504 KB Output is correct
32 Correct 11 ms 5496 KB Output is correct
33 Correct 16 ms 5716 KB Output is correct
34 Correct 13 ms 5760 KB Output is correct
35 Correct 33 ms 5760 KB Output is correct
36 Correct 12 ms 5860 KB Output is correct
37 Correct 15 ms 5888 KB Output is correct
38 Correct 45 ms 5888 KB Output is correct
39 Correct 14 ms 6016 KB Output is correct
40 Correct 17 ms 6008 KB Output is correct
41 Correct 74 ms 6016 KB Output is correct
42 Correct 20 ms 6144 KB Output is correct
43 Correct 18 ms 6144 KB Output is correct
44 Correct 75 ms 6016 KB Output is correct
45 Correct 23 ms 6144 KB Output is correct
46 Correct 22 ms 6192 KB Output is correct
47 Correct 102 ms 6144 KB Output is correct
48 Correct 19 ms 6272 KB Output is correct
49 Correct 26 ms 6272 KB Output is correct
50 Correct 110 ms 6244 KB Output is correct
51 Correct 22 ms 6312 KB Output is correct
52 Correct 20 ms 6400 KB Output is correct
53 Correct 118 ms 6392 KB Output is correct
54 Correct 19 ms 6400 KB Output is correct
55 Correct 19 ms 6528 KB Output is correct
56 Correct 156 ms 6596 KB Output is correct
57 Correct 23 ms 6524 KB Output is correct
58 Correct 26 ms 6528 KB Output is correct
59 Correct 167 ms 6524 KB Output is correct
60 Correct 28 ms 6648 KB Output is correct
61 Correct 28 ms 6656 KB Output is correct
62 Correct 202 ms 6656 KB Output is correct
63 Correct 160 ms 6780 KB Output is correct
64 Correct 272 ms 6776 KB Output is correct
65 Correct 211 ms 6776 KB Output is correct
66 Correct 173 ms 6780 KB Output is correct
67 Correct 160 ms 6648 KB Output is correct
68 Correct 86 ms 6648 KB Output is correct
69 Correct 66 ms 6776 KB Output is correct
70 Correct 72 ms 6776 KB Output is correct
71 Correct 57 ms 6776 KB Output is correct
72 Correct 38 ms 6648 KB Output is correct
73 Correct 66 ms 6756 KB Output is correct
74 Correct 98 ms 6752 KB Output is correct
75 Correct 111 ms 6784 KB Output is correct
76 Correct 115 ms 6836 KB Output is correct
77 Correct 116 ms 6736 KB Output is correct
78 Correct 122 ms 6836 KB Output is correct
79 Correct 75 ms 6836 KB Output is correct
80 Correct 110 ms 6776 KB Output is correct
81 Correct 89 ms 6848 KB Output is correct
82 Correct 81 ms 6836 KB Output is correct
83 Correct 120 ms 6940 KB Output is correct
84 Correct 120 ms 6836 KB Output is correct
85 Correct 138 ms 6832 KB Output is correct
86 Correct 133 ms 6836 KB Output is correct
87 Correct 117 ms 6844 KB Output is correct
88 Correct 123 ms 6832 KB Output is correct
89 Correct 143 ms 6868 KB Output is correct
90 Correct 167 ms 6840 KB Output is correct
91 Correct 141 ms 6844 KB Output is correct
92 Correct 135 ms 6740 KB Output is correct