oj.uz

Submission #500216

# Submission time Handle Problem Language Result Execution time Memory
500216 2021-12-30T13:16:06 Z Nartifact Mecho (IOI09_mecho) C++17
84 / 100
 175 ms 4352 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 = 2e9;
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 [x, y, st] = q.front(); q.pop();
        if(x == fin.fi && y == fin.se) return 1;
        forinc(i,0,3) {
            int nh = x + H[i];
            int nc = y + C[i];
            if(!valid(nh, nc) || cx[nh][nc]) continue;
            if((st + 1) / s < t[nh][nc] - tg)
                q.push({nh, nc, st + 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 = n * n + 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
84.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 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 1 ms 972 KB Output is correct
6 Correct 1 ms 972 KB Output is correct
7 Correct 73 ms 4084 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 Incorrect 1 ms 1100 KB Output isn't 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 1 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 19 ms 2344 KB Output is correct
36 Correct 6 ms 2408 KB Output is correct
37 Correct 6 ms 2404 KB Output is correct
38 Correct 24 ms 2520 KB Output is correct
39 Correct 7 ms 2636 KB Output is correct
40 Correct 7 ms 2636 KB Output is correct
41 Correct 41 ms 2728 KB Output is correct
42 Correct 7 ms 2892 KB Output is correct
43 Correct 8 ms 2892 KB Output is correct
44 Correct 39 ms 2892 KB Output is correct
45 Correct 8 ms 3088 KB Output is correct
46 Correct 8 ms 3020 KB Output is correct
47 Correct 43 ms 3108 KB Output is correct
48 Correct 9 ms 3276 KB Output is correct
49 Correct 12 ms 3268 KB Output is correct
50 Correct 54 ms 3304 KB Output is correct
51 Correct 13 ms 3432 KB Output is correct
52 Correct 13 ms 3384 KB Output is correct
53 Correct 70 ms 3516 KB Output is correct
54 Correct 14 ms 3660 KB Output is correct
55 Correct 12 ms 3688 KB Output is correct
56 Correct 77 ms 3660 KB Output is correct
57 Correct 14 ms 3780 KB Output is correct
58 Correct 14 ms 3780 KB Output is correct
59 Correct 90 ms 3904 KB Output is correct
60 Correct 18 ms 4044 KB Output is correct
61 Correct 17 ms 4044 KB Output is correct
62 Correct 113 ms 4080 KB Output is correct
63 Correct 89 ms 4044 KB Output is correct
64 Correct 175 ms 4072 KB Output is correct
65 Correct 137 ms 4076 KB Output is correct
66 Correct 115 ms 4200 KB Output is correct
67 Correct 113 ms 4072 KB Output is correct
68 Correct 46 ms 4040 KB Output is correct
69 Correct 49 ms 4000 KB Output is correct
70 Correct 48 ms 4100 KB Output is correct
71 Correct 56 ms 3988 KB Output is correct
72 Incorrect 35 ms 3980 KB Output isn't correct
73 Incorrect 36 ms 4352 KB Output isn't correct
74 Correct 68 ms 4352 KB Output is correct
75 Correct 64 ms 4348 KB Output is correct
76 Correct 80 ms 4348 KB Output is correct
77 Correct 62 ms 4352 KB Output is correct
78 Correct 74 ms 4324 KB Output is correct
79 Correct 45 ms 4320 KB Output is correct
80 Correct 65 ms 4324 KB Output is correct
81 Correct 60 ms 4300 KB Output is correct
82 Correct 59 ms 4340 KB Output is correct
83 Correct 82 ms 4284 KB Output is correct
84 Correct 63 ms 4176 KB Output is correct
85 Correct 68 ms 4164 KB Output is correct
86 Correct 72 ms 4296 KB Output is correct
87 Correct 71 ms 4284 KB Output is correct
88 Correct 87 ms 4236 KB Output is correct
89 Correct 80 ms 4232 KB Output is correct
90 Correct 103 ms 4132 KB Output is correct
91 Correct 81 ms 4128 KB Output is correct
92 Correct 88 ms 4228 KB Output is correct