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Submission #500078

# Submission time Handle Problem Language Result Execution time Memory
500078 2021-12-30T10:04:22 Z Nartifact Mecho (IOI09_mecho) C++14
95 / 100
 158 ms 4356 KB 
#include <bits/stdc++.h>
using namespace std;

#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 = 802, inf = 1e9;
const int H[] = {1, 0, -1, 0};
const int C[] = {0, 1, 0, -1};
int n, s;
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;
    memset(cx, 0, sizeof cx);
    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:82:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   82 |         int mid = l + r >> 1;
      |                   ~~^~~
mecho.cpp: At global scope:
mecho.cpp:100:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  100 | main ()
      | ^~~~
mecho.cpp: In function 'int main()':
mecho.cpp:105:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |   freopen (task ".inp", "r", stdin);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
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 ".out", "w", stdout);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
95.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 844 KB Output is correct
2 Correct 1 ms 972 KB Output is correct
3 Correct 1 ms 972 KB Output is correct
4 Correct 1 ms 972 KB Output is correct
5 Correct 0 ms 972 KB Output is correct
6 Correct 1 ms 972 KB Output is correct
7 Correct 78 ms 4092 KB Output is correct
8 Correct 1 ms 972 KB Output is correct
9 Correct 1 ms 972 KB Output is correct
10 Correct 1 ms 972 KB Output is correct
11 Correct 1 ms 972 KB Output is correct
12 Incorrect 1 ms 1100 KB Output isn't correct
13 Correct 1 ms 1100 KB Output is correct
14 Correct 1 ms 1100 KB Output is correct
15 Correct 1 ms 972 KB Output is correct
16 Correct 1 ms 972 KB Output is correct
17 Correct 1 ms 972 KB Output is correct
18 Correct 1 ms 972 KB Output is correct
19 Correct 1 ms 972 KB Output is correct
20 Correct 1 ms 972 KB Output is correct
21 Correct 1 ms 1100 KB Output is correct
22 Correct 1 ms 1100 KB Output is correct
23 Correct 1 ms 1100 KB Output is correct
24 Correct 1 ms 1100 KB Output is correct
25 Correct 1 ms 1100 KB Output is correct
26 Correct 1 ms 1100 KB Output is correct
27 Correct 1 ms 1100 KB Output is correct
28 Correct 1 ms 1100 KB Output is correct
29 Correct 1 ms 1228 KB Output is correct
30 Correct 2 ms 1228 KB Output is correct
31 Correct 1 ms 1228 KB Output is correct
32 Correct 1 ms 1228 KB Output is correct
33 Correct 4 ms 2252 KB Output is correct
34 Correct 4 ms 2252 KB Output is correct
35 Correct 23 ms 2460 KB Output is correct
36 Correct 6 ms 2444 KB Output is correct
37 Correct 7 ms 2508 KB Output is correct
38 Correct 34 ms 2516 KB Output is correct
39 Correct 7 ms 2636 KB Output is correct
40 Correct 6 ms 2656 KB Output is correct
41 Correct 29 ms 2680 KB Output is correct
42 Correct 8 ms 2860 KB Output is correct
43 Correct 7 ms 2828 KB Output is correct
44 Correct 37 ms 2904 KB Output is correct
45 Correct 11 ms 3020 KB Output is correct
46 Correct 9 ms 2996 KB Output is correct
47 Correct 44 ms 3100 KB Output is correct
48 Correct 14 ms 3192 KB Output is correct
49 Correct 10 ms 3276 KB Output is correct
50 Correct 70 ms 3200 KB Output is correct
51 Correct 15 ms 3456 KB Output is correct
52 Correct 11 ms 3412 KB Output is correct
53 Correct 70 ms 3508 KB Output is correct
54 Correct 12 ms 3660 KB Output is correct
55 Correct 14 ms 3588 KB Output is correct
56 Correct 79 ms 3700 KB Output is correct
57 Correct 16 ms 3776 KB Output is correct
58 Correct 14 ms 3776 KB Output is correct
59 Correct 100 ms 3892 KB Output is correct
60 Correct 17 ms 4044 KB Output is correct
61 Correct 15 ms 4044 KB Output is correct
62 Correct 100 ms 4084 KB Output is correct
63 Correct 95 ms 3980 KB Output is correct
64 Correct 158 ms 4072 KB Output is correct
65 Correct 156 ms 4072 KB Output is correct
66 Correct 127 ms 3968 KB Output is correct
67 Correct 109 ms 4080 KB Output is correct
68 Correct 51 ms 4036 KB Output is correct
69 Correct 39 ms 4036 KB Output is correct
70 Correct 37 ms 4008 KB Output is correct
71 Correct 42 ms 4000 KB Output is correct
72 Correct 29 ms 3996 KB Output is correct
73 Correct 46 ms 4248 KB Output is correct
74 Correct 71 ms 4232 KB Output is correct
75 Correct 62 ms 4356 KB Output is correct
76 Correct 68 ms 4352 KB Output is correct
77 Correct 77 ms 4356 KB Output is correct
78 Correct 99 ms 4208 KB Output is correct
79 Correct 58 ms 4220 KB Output is correct
80 Correct 71 ms 4332 KB Output is correct
81 Correct 68 ms 4212 KB Output is correct
82 Correct 66 ms 4324 KB Output is correct
83 Correct 75 ms 4224 KB Output is correct
84 Correct 68 ms 4280 KB Output is correct
85 Correct 67 ms 4284 KB Output is correct
86 Correct 93 ms 4256 KB Output is correct
87 Correct 72 ms 4280 KB Output is correct
88 Correct 85 ms 4236 KB Output is correct
89 Correct 95 ms 4236 KB Output is correct
90 Correct 103 ms 4236 KB Output is correct
91 Correct 88 ms 4232 KB Output is correct
92 Correct 86 ms 4120 KB Output is correct