oj.uz

Submission #500218

# Submission time Handle Problem Language Result Execution time Memory
500218 2021-12-30T13:16:53 Z Nartifact Mecho (IOI09_mecho) C++17
95 / 100
 177 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 = 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 = 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 1 ms 844 KB Output is correct
2 Correct 0 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 79 ms 4088 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 2 ms 1100 KB Output is correct
25 Correct 1 ms 1100 KB Output is correct
26 Correct 1 ms 1152 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 18 ms 2252 KB Output is correct
36 Correct 6 ms 2404 KB Output is correct
37 Correct 5 ms 2532 KB Output is correct
38 Correct 28 ms 2540 KB Output is correct
39 Correct 7 ms 2636 KB Output is correct
40 Correct 6 ms 2636 KB Output is correct
41 Correct 31 ms 2636 KB Output is correct
42 Correct 8 ms 2892 KB Output is correct
43 Correct 10 ms 2832 KB Output is correct
44 Correct 39 ms 2904 KB Output is correct
45 Correct 9 ms 3056 KB Output is correct
46 Correct 8 ms 3020 KB Output is correct
47 Correct 44 ms 3020 KB Output is correct
48 Correct 10 ms 3276 KB Output is correct
49 Correct 10 ms 3276 KB Output is correct
50 Correct 57 ms 3304 KB Output is correct
51 Correct 12 ms 3388 KB Output is correct
52 Correct 13 ms 3516 KB Output is correct
53 Correct 90 ms 3496 KB Output is correct
54 Correct 14 ms 3584 KB Output is correct
55 Correct 12 ms 3660 KB Output is correct
56 Correct 77 ms 3700 KB Output is correct
57 Correct 16 ms 3776 KB Output is correct
58 Correct 19 ms 3784 KB Output is correct
59 Correct 83 ms 3780 KB Output is correct
60 Correct 22 ms 4040 KB Output is correct
61 Correct 16 ms 3972 KB Output is correct
62 Correct 102 ms 4204 KB Output is correct
63 Correct 99 ms 4072 KB Output is correct
64 Correct 177 ms 4080 KB Output is correct
65 Correct 159 ms 4040 KB Output is correct
66 Correct 114 ms 4072 KB Output is correct
67 Correct 110 ms 4076 KB Output is correct
68 Correct 52 ms 4036 KB Output is correct
69 Correct 43 ms 4028 KB Output is correct
70 Correct 37 ms 4004 KB Output is correct
71 Correct 30 ms 3980 KB Output is correct
72 Correct 31 ms 4020 KB Output is correct
73 Correct 38 ms 4300 KB Output is correct
74 Correct 56 ms 4348 KB Output is correct
75 Correct 59 ms 4352 KB Output is correct
76 Correct 58 ms 4252 KB Output is correct
77 Correct 75 ms 4356 KB Output is correct
78 Correct 64 ms 4300 KB Output is correct
79 Correct 55 ms 4328 KB Output is correct
80 Correct 57 ms 4324 KB Output is correct
81 Correct 86 ms 4328 KB Output is correct
82 Correct 60 ms 4324 KB Output is correct
83 Correct 94 ms 4288 KB Output is correct
84 Correct 76 ms 4284 KB Output is correct
85 Correct 64 ms 4280 KB Output is correct
86 Correct 75 ms 4292 KB Output is correct
87 Correct 104 ms 4276 KB Output is correct
88 Correct 90 ms 4232 KB Output is correct
89 Correct 75 ms 4136 KB Output is correct
90 Correct 80 ms 4172 KB Output is correct
91 Correct 161 ms 4128 KB Output is correct
92 Correct 87 ms 4116 KB Output is correct