oj.uz

Submission #747793

# Submission time Handle Problem Language Result Execution time Memory
747793 2023-05-24T17:33:23 Z AverageAmogusEnjoyer Mecho (IOI09_mecho) C++17
30 / 100
 742 ms 6592 KB 
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using indexed_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define all(x) x.begin(), x.end() 
#define sz(x) (int) x.size()
#define pb push_back
#define ll long long
#define nl '\n'

/*

Mecho can only walk on grass and cannot go through trees or hives, and he can make at most S steps per minute.
every minute
he eats or 
he leaves immediately and takes up to S steps through the forest as described above

bees spread to grassy cells

trees = no one can go there

m = mecho, grassy cells => i will replace with g

g = grassy

d = mecho home; bees cannot go / pass here

h = hive

*/

const int N = 810;

char grid[N][N];
int stepsMecho[N][N], stepsBee[N][N];
int n, s;
array<int, 2> Mecho, MechoHouse;
vector<array<int, 2>> Bee;
vector<array<int,2>> moves = {{-1,0},{1,0},{0,-1},{0,1}};

struct m{
	bool isMecho;
	int x,y;
};

bool good(int x, int y) {
	return 0 <= x && x < n && 0 <= y && y < n && grid[x][y] != 'T';
}

bool isHome(int x, int y) {
	return x == MechoHouse[0] && y == MechoHouse[1];
}

void debug() {
	cout << "Mecho: " << nl;
	for (int i=0;i<n;i++) {
		for (int j=0;j<n;j++) {
			cout << stepsMecho[i][j] << " ";
		}
		cout << nl;
	}
	cout << "Bees: " << nl;
	for (int i=0;i<n;i++) {
		for (int j=0;j<n;j++) {
			cout << stepsBee[i][j] << " ";
		}
		cout << nl;
	}
}

bool bs(int steps) {
	memset(stepsMecho,-1,sizeof(stepsMecho));
	memset(stepsBee,-1,sizeof(stepsBee));
	queue<m> q, q2;
	q2.push(m{true,Mecho[0],Mecho[1]});
	stepsMecho[Mecho[0]][Mecho[1]] = 0;
	for (auto [x,y]:Bee) {
		q.push(m{false,x,y});
		stepsBee[x][y]=0;
	}
	while(!q.empty()) {
		m v = q.front(); q.pop();
		if (stepsBee[v.x][v.y] == steps) { q2.push(v); continue; }
 		for (auto [addx,addy]: moves) {
			int nx = v.x + addx, ny = v.y + addy;
			if (good(nx,ny) && !isHome(nx,ny) && stepsBee[nx][ny] == -1) {
				q.push(m{false,nx,ny});
				stepsBee[nx][ny] = stepsBee[v.x][v.y]+1;
			}
		}
	}
	for (int i=0;i<n;i++)
		for (int j=0;j<n;j++)
			if (stepsBee[i][j] != -1)
				stepsBee[i][j] = 0;
	while(!q2.empty()) {
		m v = q2.front(); q2.pop();
		if (v.isMecho) {
			if (stepsBee[v.x][v.y] != -1 && stepsBee[v.x][v.y] <= (stepsMecho[v.x][v.y]+s-1)/s) { continue; }
			for (auto [addx,addy]: moves) {
				int nx = v.x + addx, ny = v.y + addy;
				if (good(nx,ny) && stepsMecho[nx][ny] == -1 && (stepsBee[nx][ny] == -1 || stepsBee[nx][ny] > (stepsMecho[v.x][v.y]+s)/s)) {
					if (isHome(nx,ny)) { return 1; }
					stepsMecho[nx][ny] = stepsMecho[v.x][v.y]+1;
					q2.push(m{true,nx,ny});
				}
			}
		} else {
			for (auto [addx,addy]: moves) {
				int nx = v.x + addx, ny = v.y + addy;
				if (good(nx,ny) && !isHome(nx,ny) && stepsBee[nx][ny] == -1) {
					q2.push(m{false,nx,ny});
					stepsBee[nx][ny] = stepsBee[v.x][v.y]+1;
				}
			}
		}
	}
	return 0;
}

signed main() {
	// freopen(".in", "r", stdin);
	// freopen(".out", "w", stdout);
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin >> n >> s;
	for (int i=0;i<n;i++)
		for (int j=0;j<n;j++) {
			cin >> grid[i][j];
			if (grid[i][j]=='M') {
				grid[i][j] = 'G';
				Mecho = {i,j};
			}
			if (grid[i][j]=='H') {
				Bee.pb({i,j});
			}
			if (grid[i][j]=='D') {
				MechoHouse = {i,j};
			}
		}
	int lo = 0, hi = 1e9;
	while(lo<=hi) {
		int mid = (lo+hi)/2;
		if (bs(mid)) {
			lo = mid + 1;
		} else {
			if (mid==0) {
				cout << -1;
				return 0;
			}
			hi = mid - 1;
		}
	}
	cout << lo;
}

Subtask #1
30.0 / 100.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 5460 KB Output isn't correct
2 Incorrect 8 ms 5460 KB Output isn't correct
3 Incorrect 6 ms 5460 KB Output isn't correct
4 Incorrect 7 ms 5332 KB Output isn't correct
5 Incorrect 7 ms 5460 KB Output isn't correct
6 Correct 7 ms 5468 KB Output is correct
7 Correct 605 ms 6376 KB Output is correct
8 Correct 7 ms 5464 KB Output is correct
9 Correct 7 ms 5460 KB Output is correct
10 Correct 9 ms 5468 KB Output is correct
11 Correct 10 ms 5468 KB Output is correct
12 Incorrect 8 ms 5460 KB Output isn't correct
13 Incorrect 9 ms 5460 KB Output isn't correct
14 Correct 17 ms 5520 KB Output is correct
15 Incorrect 7 ms 5460 KB Output isn't correct
16 Correct 7 ms 5460 KB Output is correct
17 Incorrect 9 ms 5472 KB Output isn't correct
18 Correct 7 ms 5460 KB Output is correct
19 Incorrect 10 ms 5480 KB Output isn't correct
20 Correct 8 ms 5480 KB Output is correct
21 Incorrect 8 ms 5460 KB Output isn't correct
22 Correct 8 ms 5484 KB Output is correct
23 Incorrect 8 ms 5500 KB Output isn't correct
24 Correct 8 ms 5460 KB Output is correct
25 Incorrect 8 ms 5508 KB Output isn't correct
26 Correct 11 ms 5512 KB Output is correct
27 Incorrect 10 ms 5516 KB Output isn't correct
28 Correct 8 ms 5516 KB Output is correct
29 Incorrect 13 ms 5460 KB Output isn't correct
30 Correct 8 ms 5460 KB Output is correct
31 Incorrect 12 ms 5516 KB Output isn't correct
32 Correct 10 ms 5460 KB Output is correct
33 Incorrect 55 ms 5716 KB Output isn't correct
34 Correct 44 ms 5716 KB Output is correct
35 Correct 88 ms 5728 KB Output is correct
36 Incorrect 68 ms 5716 KB Output isn't correct
37 Correct 70 ms 5716 KB Output is correct
38 Correct 106 ms 5716 KB Output is correct
39 Incorrect 86 ms 5808 KB Output isn't correct
40 Correct 73 ms 5800 KB Output is correct
41 Correct 158 ms 5716 KB Output is correct
42 Incorrect 101 ms 5844 KB Output isn't correct
43 Correct 87 ms 5844 KB Output is correct
44 Correct 163 ms 5844 KB Output is correct
45 Incorrect 114 ms 5844 KB Output isn't correct
46 Correct 104 ms 5876 KB Output is correct
47 Correct 225 ms 5888 KB Output is correct
48 Incorrect 137 ms 5920 KB Output isn't correct
49 Correct 119 ms 5916 KB Output is correct
50 Correct 239 ms 5940 KB Output is correct
51 Incorrect 171 ms 5972 KB Output isn't correct
52 Correct 138 ms 5844 KB Output is correct
53 Correct 279 ms 5972 KB Output is correct
54 Incorrect 176 ms 5996 KB Output isn't correct
55 Correct 161 ms 5996 KB Output is correct
56 Correct 342 ms 6092 KB Output is correct
57 Incorrect 206 ms 6032 KB Output isn't correct
58 Correct 196 ms 6040 KB Output is correct
59 Correct 392 ms 6052 KB Output is correct
60 Incorrect 233 ms 6072 KB Output isn't correct
61 Correct 209 ms 6072 KB Output is correct
62 Correct 430 ms 6220 KB Output is correct
63 Incorrect 652 ms 6100 KB Output isn't correct
64 Correct 742 ms 6216 KB Output is correct
65 Correct 739 ms 6100 KB Output is correct
66 Incorrect 693 ms 6100 KB Output isn't correct
67 Correct 642 ms 6100 KB Output is correct
68 Incorrect 653 ms 6140 KB Output isn't correct
69 Correct 668 ms 6132 KB Output is correct
70 Correct 665 ms 6220 KB Output is correct
71 Correct 640 ms 6220 KB Output is correct
72 Incorrect 678 ms 6128 KB Output isn't correct
73 Incorrect 524 ms 6580 KB Output isn't correct
74 Correct 532 ms 6556 KB Output is correct
75 Correct 551 ms 6564 KB Output is correct
76 Correct 548 ms 6524 KB Output is correct
77 Correct 539 ms 6524 KB Output is correct
78 Correct 546 ms 6484 KB Output is correct
79 Correct 557 ms 6484 KB Output is correct
80 Correct 566 ms 6480 KB Output is correct
81 Correct 572 ms 6592 KB Output is correct
82 Correct 597 ms 6484 KB Output is correct
83 Incorrect 595 ms 6416 KB Output isn't correct
84 Correct 618 ms 6424 KB Output is correct
85 Correct 593 ms 6356 KB Output is correct
86 Correct 601 ms 6392 KB Output is correct
87 Correct 587 ms 6476 KB Output is correct
88 Incorrect 562 ms 6344 KB Output isn't correct
89 Correct 595 ms 6336 KB Output is correct
90 Correct 578 ms 6376 KB Output is correct
91 Correct 573 ms 6332 KB Output is correct
92 Correct 556 ms 6348 KB Output is correct