oj.uz

답안 #547374

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
547374 2022-04-10T14:24:58 Z pancankes Mecho (IOI09_mecho) C++17
57 / 100
 206 ms 11720 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]=INF;
    queue<pair<int,int>>q;
    if (bee[start.first][start.second]-t>=0) 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]==INF&&(bee[x][y]-t)>ceil(dist[c.first][c.second]+1)/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]!=INF) 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;
    }
    if (!check(0)) cout << -1 << endl;
    else 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
57.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 420 KB Output is correct
7 Correct 99 ms 11304 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 0 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 Correct 1 ms 852 KB Output is correct
15 Correct 0 ms 468 KB Output is correct
16 Correct 0 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 1 ms 596 KB Output is correct
20 Correct 0 ms 596 KB Output is correct
21 Correct 1 ms 596 KB Output is correct
22 Correct 1 ms 596 KB Output is correct
23 Correct 1 ms 724 KB Output is correct
24 Correct 1 ms 724 KB Output is correct
25 Correct 1 ms 852 KB Output is correct
26 Correct 1 ms 852 KB Output is correct
27 Incorrect 1 ms 940 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 980 KB Output isn't correct
32 Correct 1 ms 980 KB Output is correct
33 Incorrect 16 ms 4800 KB Output isn't correct
34 Incorrect 18 ms 4868 KB Output isn't correct
35 Correct 22 ms 4896 KB Output is correct
36 Incorrect 19 ms 5460 KB Output isn't correct
37 Incorrect 25 ms 5460 KB Output isn't correct
38 Correct 30 ms 5460 KB Output is correct
39 Incorrect 26 ms 6100 KB Output isn't correct
40 Incorrect 33 ms 6128 KB Output isn't correct
41 Correct 39 ms 6180 KB Output is correct
42 Incorrect 31 ms 6996 KB Output isn't correct
43 Incorrect 38 ms 7064 KB Output isn't correct
44 Correct 47 ms 7076 KB Output is correct
45 Incorrect 37 ms 7636 KB Output isn't correct
46 Incorrect 54 ms 7636 KB Output isn't correct
47 Correct 63 ms 7764 KB Output is correct
48 Incorrect 44 ms 8412 KB Output isn't correct
49 Incorrect 55 ms 8384 KB Output isn't correct
50 Correct 87 ms 8440 KB Output is correct
51 Incorrect 53 ms 9088 KB Output isn't correct
52 Incorrect 63 ms 9044 KB Output isn't correct
53 Correct 90 ms 9100 KB Output is correct
54 Incorrect 59 ms 9684 KB Output isn't correct
55 Incorrect 72 ms 9760 KB Output isn't correct
56 Correct 112 ms 9876 KB Output is correct
57 Incorrect 68 ms 10348 KB Output isn't correct
58 Incorrect 82 ms 10356 KB Output isn't correct
59 Correct 128 ms 10548 KB Output is correct
60 Incorrect 81 ms 11036 KB Output isn't correct
61 Incorrect 97 ms 11212 KB Output isn't correct
62 Correct 141 ms 11112 KB Output is correct
63 Correct 128 ms 11120 KB Output is correct
64 Correct 206 ms 11124 KB Output is correct
65 Correct 193 ms 11212 KB Output is correct
66 Correct 154 ms 11124 KB Output is correct
67 Correct 128 ms 11128 KB Output is correct
68 Correct 63 ms 11168 KB Output is correct
69 Correct 61 ms 11184 KB Output is correct
70 Correct 58 ms 11092 KB Output is correct
71 Correct 52 ms 11120 KB Output is correct
72 Incorrect 49 ms 11144 KB Output isn't correct
73 Incorrect 49 ms 11716 KB Output isn't correct
74 Correct 81 ms 11696 KB Output is correct
75 Correct 82 ms 11720 KB Output is correct
76 Correct 74 ms 11700 KB Output is correct
77 Correct 71 ms 11656 KB Output is correct
78 Correct 87 ms 11596 KB Output is correct
79 Correct 76 ms 11644 KB Output is correct
80 Correct 76 ms 11644 KB Output is correct
81 Correct 80 ms 11604 KB Output is correct
82 Correct 92 ms 11640 KB Output is correct
83 Correct 90 ms 11556 KB Output is correct
84 Correct 98 ms 11464 KB Output is correct
85 Correct 95 ms 11664 KB Output is correct
86 Correct 88 ms 11556 KB Output is correct
87 Correct 94 ms 11552 KB Output is correct
88 Correct 93 ms 11432 KB Output is correct
89 Correct 99 ms 11452 KB Output is correct
90 Correct 100 ms 11456 KB Output is correct
91 Correct 104 ms 11432 KB Output is correct
92 Correct 120 ms 11488 KB Output is correct