oj.uz

Submission #547342

# Submission time Handle Problem Language Result Execution time Memory
547342 2022-04-10T13:21:50 Z pancankes Mecho (IOI09_mecho) C++17
29 / 100
 196 ms 12344 KB 
#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <cmath>
using namespace std;
#define int long long
const int INF=1e18;
const int MAXN=801;

int n,s,ans=0;
string grid[MAXN];
int bee[MAXN][MAXN],dist[MAXN][MAXN];
vector<pair<int,int>> hives;
pair<int,int> start,dest;

int dx[4]{1, -1, 0, 0}, dy[4]{0, 0, 1, -1};
bool inside(int x, int y) {
	return (x > -1 && x < n && y > -1 && y < n && grid[x][y] != 'T');
}

void setIO(string name="") { 
    ios_base::sync_with_stdio(0); cin.tie(0); 
    if (!name.empty()) {
        freopen((name+".in").c_str(), "r", stdin); 
        freopen((name+".out").c_str(), "w", stdout);
    }
}

// check if after eating for t seconds,
// is it possible to reach the destination
bool check(int t)
{
    for (int i=0; i<n; i++)
        for (int j=0; j<n; j++)
            dist[i][j]=-1;
    queue<pair<int,int>>q;
    q.push(start);
    dist[start.first][start.second]=0;
    while (!q.empty())
    {
        pair<int,int> c=q.front();
        q.pop();

        for (int i=0; i<4; i++)
        {
            int x=c.first+dx[i],y=c.second+dy[i];
            // if i can usually get there in 7 step
            // taking 2 steps a minute i can get there in ceil(7/2) steps
            if (inside(x,y)&&dist[x][y]==-1&&(bee[x][y]-t)>=ceil((double)(dist[c.first][c.second]+1)/(double)s))
            {
                dist[x][y]=dist[c.first][c.second]+1;
                q.push({x,y});
            }
        }
    }
    // cout << t << endl;
    // for (int i=0; i<n; i++) {for (int j=0; j<n; j++) cout << dist[i][j] << " "; cout << endl;}
    if (dist[dest.first][dest.second]!=-1) return true;
    else return false;
}

int32_t main()
{
    cin >> n >> s;
    for (int i=0; i<n; i++) cin >> grid[i];
    for (int i=0; i<n; i++)
        for (int j=0; j<n; j++)
        {
            if (grid[i][j]=='M') start={i,j};
            if (grid[i][j]=='D') dest={i,j};
            if (grid[i][j]=='H') hives.push_back({i,j});
            bee[i][j]=INF;
        }
    // multisource bfs to find the distances of cells from hive
    queue<pair<int,int>> q;
    for (int i=0; i<hives.size(); i++) {
        q.push(hives[i]);
        bee[hives[i].first][hives[i].second]=0;
    }
    while (!q.empty())
    {
        pair<int,int> c=q.front();
        q.pop();
        for (int i=0; i<4; i++)
        {
            int x=c.first+dx[i],y=c.second+dy[i];
            if (inside(x,y)&&grid[x][y]!='D'&&bee[x][y]==INF)
            {
                bee[x][y]=bee[c.first][c.second]+1;
                q.push({x,y});
            }
        }
    }
    //for (int i=0; i<n; i++) {for (int j=0; j<n; j++) cout << bee[i][j] << " "; cout << endl;} cout << endl;
    int lo=0,hi=2000;
    while (lo<=hi)
    {
        int mid=lo+(hi-lo)/2;
        // cout << mid << endl;
        if (check(mid))
        {
            ans=max(ans,mid);
            lo=mid+1;
        }
        else hi=mid-1;
    }
    cout << ans << endl;
}

Compilation message

mecho.cpp: In function 'int32_t main()':
mecho.cpp:79:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |     for (int i=0; i<hives.size(); i++) {
      |                   ~^~~~~~~~~~~~~
mecho.cpp: In function 'void setIO(std::string)':
mecho.cpp:27:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         freopen((name+".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen((name+".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
29.0 / 100.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 340 KB Output isn't correct
2 Incorrect 1 ms 340 KB Output isn't correct
3 Incorrect 1 ms 340 KB Output isn't correct
4 Incorrect 1 ms 340 KB Output isn't correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 111 ms 11928 KB Output is correct
8 Incorrect 1 ms 340 KB Output isn't correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Incorrect 1 ms 852 KB Output isn't correct
13 Incorrect 1 ms 724 KB Output isn't correct
14 Incorrect 2 ms 852 KB Output isn't correct
15 Incorrect 1 ms 468 KB Output isn't correct
16 Correct 1 ms 468 KB Output is correct
17 Incorrect 1 ms 468 KB Output isn't correct
18 Correct 1 ms 468 KB Output is correct
19 Incorrect 1 ms 596 KB Output isn't correct
20 Correct 1 ms 596 KB Output is correct
21 Incorrect 1 ms 596 KB Output isn't correct
22 Correct 1 ms 596 KB Output is correct
23 Incorrect 1 ms 724 KB Output isn't correct
24 Correct 1 ms 724 KB Output is correct
25 Incorrect 1 ms 852 KB Output isn't correct
26 Correct 1 ms 852 KB Output is correct
27 Incorrect 1 ms 852 KB Output isn't correct
28 Correct 1 ms 852 KB Output is correct
29 Incorrect 1 ms 980 KB Output isn't correct
30 Correct 1 ms 980 KB Output is correct
31 Incorrect 1 ms 976 KB Output isn't correct
32 Correct 1 ms 980 KB Output is correct
33 Incorrect 19 ms 4948 KB Output isn't correct
34 Incorrect 20 ms 4940 KB Output isn't correct
35 Correct 23 ms 5004 KB Output is correct
36 Incorrect 22 ms 5708 KB Output isn't correct
37 Incorrect 25 ms 5588 KB Output isn't correct
38 Correct 29 ms 5700 KB Output is correct
39 Incorrect 28 ms 6396 KB Output isn't correct
40 Incorrect 35 ms 6492 KB Output isn't correct
41 Correct 38 ms 6352 KB Output is correct
42 Incorrect 35 ms 7316 KB Output isn't correct
43 Incorrect 43 ms 7272 KB Output isn't correct
44 Correct 52 ms 7324 KB Output is correct
45 Incorrect 40 ms 8020 KB Output isn't correct
46 Incorrect 49 ms 7940 KB Output isn't correct
47 Correct 62 ms 8052 KB Output is correct
48 Incorrect 48 ms 8772 KB Output isn't correct
49 Incorrect 60 ms 8788 KB Output isn't correct
50 Correct 77 ms 8784 KB Output is correct
51 Incorrect 58 ms 9512 KB Output isn't correct
52 Incorrect 70 ms 9420 KB Output isn't correct
53 Correct 89 ms 9428 KB Output is correct
54 Incorrect 69 ms 10256 KB Output isn't correct
55 Incorrect 87 ms 10188 KB Output isn't correct
56 Correct 109 ms 10340 KB Output is correct
57 Incorrect 76 ms 10956 KB Output isn't correct
58 Incorrect 91 ms 10984 KB Output isn't correct
59 Correct 122 ms 11004 KB Output is correct
60 Incorrect 86 ms 11732 KB Output isn't correct
61 Incorrect 106 ms 11852 KB Output isn't correct
62 Correct 155 ms 11724 KB Output is correct
63 Correct 117 ms 11724 KB Output is correct
64 Correct 196 ms 11740 KB Output is correct
65 Correct 178 ms 11748 KB Output is correct
66 Incorrect 157 ms 11736 KB Output isn't correct
67 Incorrect 120 ms 11760 KB Output isn't correct
68 Correct 66 ms 11856 KB Output is correct
69 Correct 55 ms 11832 KB Output is correct
70 Correct 54 ms 11724 KB Output is correct
71 Correct 48 ms 11756 KB Output is correct
72 Incorrect 41 ms 11696 KB Output isn't correct
73 Incorrect 48 ms 12244 KB Output isn't correct
74 Correct 69 ms 12300 KB Output is correct
75 Correct 75 ms 12244 KB Output is correct
76 Correct 69 ms 12240 KB Output is correct
77 Correct 67 ms 12288 KB Output is correct
78 Incorrect 85 ms 12200 KB Output isn't correct
79 Correct 66 ms 12208 KB Output is correct
80 Correct 78 ms 12236 KB Output is correct
81 Correct 85 ms 12344 KB Output is correct
82 Correct 77 ms 12236 KB Output is correct
83 Correct 92 ms 12168 KB Output is correct
84 Correct 84 ms 12240 KB Output is correct
85 Correct 87 ms 12188 KB Output is correct
86 Correct 85 ms 12188 KB Output is correct
87 Correct 85 ms 12188 KB Output is correct
88 Correct 93 ms 12188 KB Output is correct
89 Correct 94 ms 12108 KB Output is correct
90 Correct 94 ms 12196 KB Output is correct
91 Correct 91 ms 11976 KB Output is correct
92 Correct 92 ms 12060 KB Output is correct