Submission #500035

# Submission time Handle Problem Language Result Execution time Memory
500035 2021-12-30T09:46:44 Z Nartifact Mecho (IOI09_mecho) C++14
73 / 100
206 ms 7824 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];
bool cx[N][N];
pii sta, fin;

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

struct adt {int x, y, step;};

bool ok (const int& tg)
{
    queue <adt> q;
    forinc(i,1,n) forinc(j,1,n) cx[i][j] = 0;
    q.push({sta.fi, sta.se, 0});
    cx[sta.fi][sta.se] = 1;
    while(q.size()) {
        auto tmp = q.front(); q.pop();
        if(tmp.x == fin.fi && tmp.y == fin.se) return 1;
        forinc(i,0,3) {
            int nh = tmp.x + H[i];
            int nc = tmp.y + C[i];
            if(valid(nh, nc) && !cx[nh][nc] && (tmp.step + 1) / s < t[nh][nc] - tg) {
                q.push({nh, nc, tmp.step + 1});
                cx[nh][nc] = 1;
            }
        }
    }
    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
    int last = 0;
    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) && t[nh][nc] > t[x.fi][x.se] + 1) {
                t[nh][nc] = t[x.fi][x.se] + 1;
                last = max(last, t[nh][nc]);
                q.push({nh, nc});
            }
        }
    }

    // binary search
    int l = 0, r = last, 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);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Incorrect 1 ms 332 KB Output isn't correct
3 Correct 1 ms 332 KB Output is correct
4 Incorrect 1 ms 332 KB Output isn't correct
5 Correct 0 ms 332 KB Output is correct
6 Incorrect 1 ms 332 KB Output isn't correct
7 Incorrect 109 ms 7460 KB Output isn't correct
8 Correct 0 ms 332 KB Output is correct
9 Correct 0 ms 332 KB Output is correct
10 Correct 0 ms 332 KB Output is correct
11 Correct 0 ms 332 KB Output is correct
12 Incorrect 1 ms 588 KB Output isn't correct
13 Incorrect 1 ms 588 KB Output isn't correct
14 Correct 1 ms 588 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 1 ms 332 KB Output is correct
17 Correct 1 ms 460 KB Output is correct
18 Correct 1 ms 460 KB Output is correct
19 Correct 1 ms 460 KB Output is correct
20 Correct 1 ms 460 KB Output is correct
21 Correct 1 ms 460 KB Output is correct
22 Correct 1 ms 460 KB Output is correct
23 Correct 1 ms 588 KB Output is correct
24 Correct 1 ms 640 KB Output is correct
25 Correct 1 ms 588 KB Output is correct
26 Correct 1 ms 588 KB Output is correct
27 Correct 1 ms 716 KB Output is correct
28 Correct 1 ms 716 KB Output is correct
29 Correct 1 ms 716 KB Output is correct
30 Correct 1 ms 716 KB Output is correct
31 Correct 1 ms 716 KB Output is correct
32 Correct 1 ms 720 KB Output is correct
33 Correct 7 ms 3280 KB Output is correct
34 Correct 5 ms 3268 KB Output is correct
35 Correct 42 ms 3308 KB Output is correct
36 Correct 6 ms 3708 KB Output is correct
37 Correct 8 ms 3788 KB Output is correct
38 Correct 30 ms 3712 KB Output is correct
39 Correct 10 ms 4172 KB Output is correct
40 Correct 6 ms 4172 KB Output is correct
41 Correct 39 ms 4256 KB Output is correct
42 Correct 10 ms 4572 KB Output is correct
43 Correct 8 ms 4644 KB Output is correct
44 Correct 47 ms 4596 KB Output is correct
45 Correct 10 ms 4992 KB Output is correct
46 Correct 10 ms 5068 KB Output is correct
47 Correct 61 ms 5120 KB Output is correct
48 Correct 16 ms 5452 KB Output is correct
49 Correct 14 ms 5532 KB Output is correct
50 Correct 93 ms 5556 KB Output is correct
51 Correct 19 ms 5940 KB Output is correct
52 Correct 20 ms 5976 KB Output is correct
53 Correct 84 ms 5956 KB Output is correct
54 Correct 21 ms 6312 KB Output is correct
55 Correct 16 ms 6416 KB Output is correct
56 Correct 109 ms 6440 KB Output is correct
57 Correct 20 ms 6780 KB Output is correct
58 Correct 19 ms 6836 KB Output is correct
59 Correct 154 ms 6852 KB Output is correct
60 Correct 22 ms 7196 KB Output is correct
61 Correct 18 ms 7176 KB Output is correct
62 Correct 150 ms 7288 KB Output is correct
63 Correct 111 ms 7268 KB Output is correct
64 Correct 206 ms 7236 KB Output is correct
65 Correct 196 ms 7272 KB Output is correct
66 Correct 136 ms 7264 KB Output is correct
67 Correct 119 ms 7272 KB Output is correct
68 Correct 52 ms 7328 KB Output is correct
69 Correct 46 ms 7320 KB Output is correct
70 Correct 43 ms 7284 KB Output is correct
71 Correct 49 ms 7276 KB Output is correct
72 Incorrect 34 ms 7272 KB Output isn't correct
73 Incorrect 47 ms 7768 KB Output isn't correct
74 Correct 76 ms 7824 KB Output is correct
75 Correct 68 ms 7788 KB Output is correct
76 Correct 69 ms 7764 KB Output is correct
77 Correct 85 ms 7812 KB Output is correct
78 Correct 90 ms 7704 KB Output is correct
79 Correct 56 ms 7748 KB Output is correct
80 Correct 69 ms 7716 KB Output is correct
81 Correct 70 ms 7712 KB Output is correct
82 Correct 59 ms 7760 KB Output is correct
83 Correct 96 ms 7684 KB Output is correct
84 Correct 84 ms 7624 KB Output is correct
85 Correct 80 ms 7580 KB Output is correct
86 Correct 89 ms 7644 KB Output is correct
87 Correct 88 ms 7680 KB Output is correct
88 Correct 94 ms 7548 KB Output is correct
89 Correct 94 ms 7592 KB Output is correct
90 Correct 121 ms 7532 KB Output is correct
91 Correct 97 ms 7492 KB Output is correct
92 Correct 95 ms 7584 KB Output is correct