oj.uz

Submission #500047

# Submission time Handle Problem Language Result Execution time Memory
500047 2021-12-30T09:53:05 Z Nartifact Mecho (IOI09_mecho) C++14
95 / 100
 172 ms 7836 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
    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;
                q.push({nh, nc});
            }
        }
    }
	t[fin.fi][fin.se] = inf;
    // binary search
    int l = 0, r = t[sta.fi][sta.se] - 1, 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:83:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   83 |         int mid = l + r >> 1;
      |                   ~~^~~
mecho.cpp: At global scope:
mecho.cpp:101:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  101 | main ()
      | ^~~~
mecho.cpp: In function 'int main()':
mecho.cpp:106:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |   freopen (task ".inp", "r", stdin);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:107:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |   freopen (task ".out", "w", stdout);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
95.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 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 332 KB Output is correct
7 Correct 77 ms 7480 KB Output is 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 Correct 1 ms 588 KB Output is correct
14 Correct 1 ms 716 KB Output is correct
15 Correct 0 ms 332 KB Output is correct
16 Correct 0 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 0 ms 460 KB Output is correct
21 Correct 0 ms 460 KB Output is correct
22 Correct 0 ms 460 KB Output is correct
23 Correct 0 ms 588 KB Output is correct
24 Correct 1 ms 588 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 716 KB Output is correct
33 Correct 5 ms 3276 KB Output is correct
34 Correct 4 ms 3276 KB Output is correct
35 Correct 18 ms 3316 KB Output is correct
36 Correct 5 ms 3788 KB Output is correct
37 Correct 6 ms 3788 KB Output is correct
38 Correct 23 ms 3788 KB Output is correct
39 Correct 7 ms 4172 KB Output is correct
40 Correct 7 ms 4172 KB Output is correct
41 Correct 34 ms 4172 KB Output is correct
42 Correct 8 ms 4556 KB Output is correct
43 Correct 8 ms 4556 KB Output is correct
44 Correct 38 ms 4688 KB Output is correct
45 Correct 9 ms 5096 KB Output is correct
46 Correct 12 ms 5068 KB Output is correct
47 Correct 53 ms 5116 KB Output is correct
48 Correct 11 ms 5536 KB Output is correct
49 Correct 11 ms 5452 KB Output is correct
50 Correct 60 ms 5452 KB Output is correct
51 Correct 14 ms 5964 KB Output is correct
52 Correct 12 ms 5888 KB Output is correct
53 Correct 64 ms 5976 KB Output is correct
54 Correct 14 ms 6476 KB Output is correct
55 Correct 13 ms 6348 KB Output is correct
56 Correct 91 ms 6408 KB Output is correct
57 Correct 16 ms 6724 KB Output is correct
58 Correct 16 ms 6732 KB Output is correct
59 Correct 99 ms 6984 KB Output is correct
60 Correct 18 ms 7244 KB Output is correct
61 Correct 17 ms 7244 KB Output is correct
62 Correct 102 ms 7276 KB Output is correct
63 Correct 104 ms 7236 KB Output is correct
64 Correct 172 ms 7272 KB Output is correct
65 Correct 157 ms 7224 KB Output is correct
66 Correct 111 ms 7244 KB Output is correct
67 Correct 111 ms 7264 KB Output is correct
68 Correct 47 ms 7244 KB Output is correct
69 Correct 43 ms 7320 KB Output is correct
70 Correct 35 ms 7284 KB Output is correct
71 Correct 32 ms 7276 KB Output is correct
72 Correct 30 ms 7244 KB Output is correct
73 Correct 38 ms 7836 KB Output is correct
74 Correct 57 ms 7824 KB Output is correct
75 Correct 75 ms 7820 KB Output is correct
76 Correct 59 ms 7820 KB Output is correct
77 Correct 61 ms 7812 KB Output is correct
78 Correct 66 ms 7708 KB Output is correct
79 Correct 52 ms 7744 KB Output is correct
80 Correct 57 ms 7764 KB Output is correct
81 Correct 67 ms 7768 KB Output is correct
82 Correct 64 ms 7656 KB Output is correct
83 Correct 73 ms 7644 KB Output is correct
84 Correct 63 ms 7684 KB Output is correct
85 Correct 63 ms 7688 KB Output is correct
86 Correct 80 ms 7684 KB Output is correct
87 Correct 69 ms 7620 KB Output is correct
88 Correct 75 ms 7500 KB Output is correct
89 Correct 71 ms 7552 KB Output is correct
90 Correct 91 ms 7580 KB Output is correct
91 Correct 90 ms 7500 KB Output is correct
92 Correct 108 ms 7544 KB Output is correct