oj.uz

Submission #500220

# Submission time Handle Problem Language Result Execution time Memory
500220 2021-12-30T13:18:29 Z Nartifact Mecho (IOI09_mecho) C++17
84 / 100
 175 ms 4364 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 pii pair <int,int>
#define fi first
#define se second

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 > 0 && y > 0 && x <= n && y <= n && a[x][y] != 'T';
}

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

bool ok (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:76:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   76 |         int mid = l + r >> 1;
      |                   ~~^~~
mecho.cpp: At global scope:
mecho.cpp:94:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   94 | main ()
      | ^~~~
mecho.cpp: In function 'int main()':
mecho.cpp:99:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |   freopen (task ".inp", "r", stdin);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:100:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |   freopen (task ".out", "w", stdout);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
84.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 972 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 75 ms 4204 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 924 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 1100 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 17 ms 2252 KB Output is correct
36 Correct 6 ms 2508 KB Output is correct
37 Correct 5 ms 2508 KB Output is correct
38 Correct 23 ms 2508 KB Output is correct
39 Correct 6 ms 2600 KB Output is correct
40 Correct 6 ms 2636 KB Output is correct
41 Correct 29 ms 2636 KB Output is correct
42 Correct 7 ms 2856 KB Output is correct
43 Correct 8 ms 2892 KB Output is correct
44 Correct 35 ms 2908 KB Output is correct
45 Correct 9 ms 3020 KB Output is correct
46 Correct 9 ms 3020 KB Output is correct
47 Correct 45 ms 3000 KB Output is correct
48 Correct 9 ms 3276 KB Output is correct
49 Correct 10 ms 3228 KB Output is correct
50 Correct 68 ms 3296 KB Output is correct
51 Correct 12 ms 3468 KB Output is correct
52 Correct 13 ms 3404 KB Output is correct
53 Correct 65 ms 3496 KB Output is correct
54 Correct 12 ms 3652 KB Output is correct
55 Correct 15 ms 3688 KB Output is correct
56 Correct 78 ms 3588 KB Output is correct
57 Correct 17 ms 3828 KB Output is correct
58 Correct 16 ms 3900 KB Output is correct
59 Correct 85 ms 3896 KB Output is correct
60 Correct 15 ms 4044 KB Output is correct
61 Correct 17 ms 3960 KB Output is correct
62 Correct 105 ms 4080 KB Output is correct
63 Correct 110 ms 4080 KB Output is correct
64 Correct 167 ms 3972 KB Output is correct
65 Correct 175 ms 4100 KB Output is correct
66 Correct 119 ms 4072 KB Output is correct
67 Correct 107 ms 4076 KB Output is correct
68 Correct 45 ms 4016 KB Output is correct
69 Correct 39 ms 4096 KB Output is correct
70 Correct 38 ms 4044 KB Output is correct
71 Correct 31 ms 3996 KB Output is correct
72 Incorrect 39 ms 3984 KB Output isn't correct
73 Incorrect 37 ms 4364 KB Output isn't correct
74 Correct 53 ms 4352 KB Output is correct
75 Correct 52 ms 4292 KB Output is correct
76 Correct 60 ms 4272 KB Output is correct
77 Correct 60 ms 4360 KB Output is correct
78 Correct 83 ms 4328 KB Output is correct
79 Correct 49 ms 4292 KB Output is correct
80 Correct 56 ms 4228 KB Output is correct
81 Correct 57 ms 4240 KB Output is correct
82 Correct 52 ms 4244 KB Output is correct
83 Correct 93 ms 4280 KB Output is correct
84 Correct 64 ms 4176 KB Output is correct
85 Correct 78 ms 4304 KB Output is correct
86 Correct 71 ms 4300 KB Output is correct
87 Correct 64 ms 4280 KB Output is correct
88 Correct 71 ms 4132 KB Output is correct
89 Correct 81 ms 4232 KB Output is correct
90 Correct 79 ms 4236 KB Output is correct
91 Correct 76 ms 4200 KB Output is correct
92 Correct 74 ms 4128 KB Output is correct