oj.uz

Submission #500233

# Submission time Handle Problem Language Result Execution time Memory
500233 2021-12-30T13:33:47 Z Nartifact Mecho (IOI09_mecho) C++17
100 / 100
 245 ms 17896 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define forinc(i,a,b) for(int i=a;i<=b;++i)
#define fordec(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define eb emplace_back
#define pii pair <int,int>
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int N = 888, inf = 1e15;
const int H[] = {1, 0, -1, 0};
const int C[] = {0, 1, 0, -1};
int n, s, cti = inf;
char a[N][N];
int t[N][N], f[N][N], m[N][N];
pii sta, fin;

bool valid (const int& x, const int& y)
{
    return x && y && x <= n && y <= n
          && a[x][y] != 'T';
}

bool ok (const int& tg)
{
    queue <pii> q; q.push(sta);
    forinc(i,1,n) forinc(j,1,n) f[i][j] = inf;
    if(tg >= t[sta.fi][sta.se]) return 0;
    f[sta.fi][sta.se] = tg;
    while(q.size()) {
        auto x = q.front(); q.pop();
        if(x == fin) return 1;
        forinc(i,0,3) {
            int nh = x.fi + H[i];
            int nc = x.se + C[i];
            if(valid(nh, nc) && f[nh][nc] > f[x.fi][x.se] + 1) {
                f[nh][nc] = f[x.fi][x.se] + 1;
                m[nh][nc] = (m[x.fi][x.se] + 1) % s;
                int diff = f[nh][nc] - tg - 1;
                diff /= s;
                diff += tg + 1;
                if(diff < t[nh][nc] || (diff == t[nh][nc] && m[nh][nc]))
                    q.push({nh, nc});
            }
        }
    }
    return 0;
}

void solve ()
{
    queue <pii> q;
    forinc(i,1,n) forinc(j,1,n) {
        t[i][j] = inf;
        if(a[i][j] == 'H') {
            q.push({i, j});
            t[i][j] = 0;
        }
        else if(a[i][j] == 'M') sta = {i, j};
        else if(a[i][j] == 'D') fin = {i, j};
    }

    // bfs bee
    while(q.size()) {
        auto x = q.front(); q.pop();
        forinc(i,0,3) {
            int nh = x.fi + H[i];
            int nc = x.se + C[i];
            if(valid(nh, nc) && a[nh][nc] != 'D' && t[nh][nc] > t[x.fi][x.se] + 1) {
                t[nh][nc] = t[x.fi][x.se] + 1;
                q.push({nh, nc});
            }
        }
    }

    // binary search
    int l = 0, r = n * n, ans = -1;
    while(l <= r) {
        int mid = l + r >> 1;
        if(ok(mid)) {
            ans = mid;
            l = mid + 1;
        }
        else r = mid - 1;
    }
    cout << ans;
}

void read ()
{
    cin >> n >> s;
    forinc(i,1,n) forinc(j,1,n)
        cin >> a[i][j];
    solve();
}

main ()
{
	#define task "ioi09_mecho"
	cin.tie(0) -> sync_with_stdio(0);
	if(fopen (task ".inp", "r")) {
		freopen (task ".inp", "r", stdin);
		freopen (task ".out", "w", stdout);
	}
    read();
	return 0;
}

Compilation message

mecho.cpp: In function 'void solve()':
mecho.cpp:85:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   85 |         int mid = l + r >> 1;
      |                   ~~^~~
mecho.cpp: At global scope:
mecho.cpp:103:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  103 | main ()
      | ^~~~
mecho.cpp: In function 'int main()':
mecho.cpp:108:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |   freopen (task ".inp", "r", stdin);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:109:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |   freopen (task ".out", "w", stdout);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 ms 332 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 160 ms 15632 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 460 KB Output is correct
10 Correct 0 ms 460 KB Output is correct
11 Correct 0 ms 460 KB Output is correct
12 Correct 1 ms 844 KB Output is correct
13 Correct 1 ms 844 KB Output is correct
14 Correct 1 ms 972 KB Output is correct
15 Correct 0 ms 460 KB Output is correct
16 Correct 1 ms 460 KB Output is correct
17 Correct 1 ms 588 KB Output is correct
18 Correct 1 ms 588 KB Output is correct
19 Correct 1 ms 588 KB Output is correct
20 Correct 0 ms 588 KB Output is correct
21 Correct 1 ms 716 KB Output is correct
22 Correct 1 ms 768 KB Output is correct
23 Correct 1 ms 844 KB Output is correct
24 Correct 1 ms 844 KB Output is correct
25 Correct 1 ms 844 KB Output is correct
26 Correct 1 ms 972 KB Output is correct
27 Correct 1 ms 972 KB Output is correct
28 Correct 1 ms 972 KB Output is correct
29 Correct 1 ms 972 KB Output is correct
30 Correct 1 ms 972 KB Output is correct
31 Correct 1 ms 1100 KB Output is correct
32 Correct 1 ms 1100 KB Output is correct
33 Correct 7 ms 5324 KB Output is correct
34 Correct 6 ms 5452 KB Output is correct
35 Correct 25 ms 7620 KB Output is correct
36 Correct 8 ms 6220 KB Output is correct
37 Correct 8 ms 6220 KB Output is correct
38 Correct 29 ms 9024 KB Output is correct
39 Correct 9 ms 6908 KB Output is correct
40 Correct 9 ms 6944 KB Output is correct
41 Correct 45 ms 10088 KB Output is correct
42 Correct 13 ms 7664 KB Output is correct
43 Correct 10 ms 7700 KB Output is correct
44 Correct 65 ms 11168 KB Output is correct
45 Correct 14 ms 8472 KB Output is correct
46 Correct 14 ms 8520 KB Output is correct
47 Correct 74 ms 12264 KB Output is correct
48 Correct 15 ms 9164 KB Output is correct
49 Correct 15 ms 9164 KB Output is correct
50 Correct 79 ms 13260 KB Output is correct
51 Correct 17 ms 9940 KB Output is correct
52 Correct 19 ms 9932 KB Output is correct
53 Correct 151 ms 14396 KB Output is correct
54 Correct 25 ms 10576 KB Output is correct
55 Correct 21 ms 10672 KB Output is correct
56 Correct 121 ms 15512 KB Output is correct
57 Correct 22 ms 11340 KB Output is correct
58 Correct 24 ms 11448 KB Output is correct
59 Correct 157 ms 16608 KB Output is correct
60 Correct 47 ms 12148 KB Output is correct
61 Correct 35 ms 12200 KB Output is correct
62 Correct 169 ms 17652 KB Output is correct
63 Correct 117 ms 17620 KB Output is correct
64 Correct 245 ms 17664 KB Output is correct
65 Correct 168 ms 17480 KB Output is correct
66 Correct 132 ms 17496 KB Output is correct
67 Correct 135 ms 17288 KB Output is correct
68 Correct 63 ms 16936 KB Output is correct
69 Correct 60 ms 17016 KB Output is correct
70 Correct 47 ms 16628 KB Output is correct
71 Correct 74 ms 16588 KB Output is correct
72 Correct 50 ms 13040 KB Output is correct
73 Correct 47 ms 17896 KB Output is correct
74 Correct 84 ms 17396 KB Output is correct
75 Correct 88 ms 17508 KB Output is correct
76 Correct 100 ms 17556 KB Output is correct
77 Correct 86 ms 17280 KB Output is correct
78 Correct 122 ms 15300 KB Output is correct
79 Correct 58 ms 14460 KB Output is correct
80 Correct 69 ms 14692 KB Output is correct
81 Correct 82 ms 14880 KB Output is correct
82 Correct 69 ms 14920 KB Output is correct
83 Correct 111 ms 15248 KB Output is correct
84 Correct 95 ms 14916 KB Output is correct
85 Correct 98 ms 15144 KB Output is correct
86 Correct 98 ms 15148 KB Output is correct
87 Correct 108 ms 15192 KB Output is correct
88 Correct 108 ms 15600 KB Output is correct
89 Correct 113 ms 15232 KB Output is correct
90 Correct 111 ms 15348 KB Output is correct
91 Correct 105 ms 15428 KB Output is correct
92 Correct 128 ms 15300 KB Output is correct