Submission #552750

# Submission time Handle Problem Language Result Execution time Memory
552750 2022-04-23T20:05:17 Z Iwanttobreakfree Mecho (IOI09_mecho) C++
54 / 100
359 ms 43556 KB
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
void bfs(queue<int>& q,vector<int>& dist,vector<vector<int>>& g,int b){
    int n=dist.size();
    while(!q.empty()){
        int u=q.front();
        //cout<<u<<' ';
        q.pop();
        for(int v:g[u]){
            if(dist[v]==-1&&v!=b){
                dist[v]=dist[u]+1;
                q.push(v);
            }
        }
    }
}
bool pos(int a,int b,int mid,int s,vector<vector<int>>& g,vector<int>& dist){
    int n=dist.size();
    vector<pair<int,int>> d(n,{-1,-1});
    queue<int> q;
    q.push(a);
    //cout<<mid<<'\n';
    if(mid>=dist[a])return false;
    d[a].first=mid;
    d[a].second=-1;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        //cout<<d[u].first<<' ';
        for(int v:g[u]){
            if(d[v].first==-1){
                d[v]=d[u];
                d[v].second++;
                if(d[v].second==s){
                    d[v].second=0;
                    d[v].first++;
                }
                if(d[v].first<dist[v])q.push(v);
            }
        }
    }
    /*for(int i=0;i<n;i++){
        for(int j=0;j<n;j++)cout<<d[i*n+j].first<<' ';
        cout<<'\n';
    }*/
    if(d[b].first==-1)return false;
    return true;
}
int main(){
    int n,s,u,v;
    char c;
    cin>>n>>s;
    vector<vector<int>> g(n*n,vector<int>());
    vector<vector<char>> grid(n,vector<char>(n));
    vector<int> dist(n*n,-1);
    queue<int> q;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            cin>>grid[i][j];
            if(grid[i][j]=='T')continue;
            else{
                if(i&&grid[i-1][j]!='T'){
                    g[i*n+j].push_back(i*n+j-n);
                    g[i*n+j-n].push_back(i*n+j);
                }
                if(j&&grid[i][j-1]!='T'){
                    g[i*n+j].push_back(i*n+j-1);
                    g[i*n+j-1].push_back(i*n+j);
                }
                if(grid[i][j]=='D'){
                    v=i*n+j;
                    dist[v]=1e9;
                }
                if(grid[i][j]=='M')u=i*n+j;
                if(grid[i][j]=='H'){
                    q.push(i*n+j);
                    dist[i*n+j]=0;
                }
            }
        }
    }
    bfs(q,dist,g,v);
    /*for(int i=0;i<n;i++){
        for(int j=0;j<n;j++)cout<<dist[i*n+j]<<' ';
        cout<<'\n';
    }*/
    int l=0,r=1e9,ans=-1;
    while(l<=r){
        int mid=(r+l)/2;
        if(pos(u,v,mid,s,g,dist)){
            l=mid+1;
            ans=mid;
        }
        else r=mid-1;
    }
    cout<<ans;
}

Compilation message

mecho.cpp: In function 'void bfs(std::queue<int>&, std::vector<int>&, std::vector<std::vector<int> >&, int)':
mecho.cpp:6:9: warning: unused variable 'n' [-Wunused-variable]
    6 |     int n=dist.size();
      |         ^
mecho.cpp: In function 'int main()':
mecho.cpp:53:10: warning: unused variable 'c' [-Wunused-variable]
   53 |     char c;
      |          ^
mecho.cpp:92:15: warning: 'v' may be used uninitialized in this function [-Wmaybe-uninitialized]
   92 |         if(pos(u,v,mid,s,g,dist)){
      |            ~~~^~~~~~~~~~~~~~~~~~
mecho.cpp:92:15: warning: 'u' may be used uninitialized in this function [-Wmaybe-uninitialized]
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Output isn't correct
2 Incorrect 0 ms 212 KB Output isn't correct
3 Incorrect 0 ms 212 KB Output isn't correct
4 Incorrect 0 ms 212 KB Output isn't correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 281 ms 43540 KB Output is correct
8 Incorrect 0 ms 212 KB Output isn't correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Incorrect 0 ms 212 KB Output isn't correct
16 Correct 1 ms 212 KB Output is correct
17 Incorrect 0 ms 212 KB Output isn't correct
18 Correct 1 ms 212 KB Output is correct
19 Incorrect 1 ms 340 KB Output isn't correct
20 Correct 0 ms 340 KB Output is correct
21 Incorrect 1 ms 340 KB Output isn't correct
22 Correct 1 ms 340 KB Output is correct
23 Incorrect 1 ms 340 KB Output isn't correct
24 Correct 1 ms 340 KB Output is correct
25 Incorrect 1 ms 468 KB Output isn't correct
26 Correct 1 ms 468 KB Output is correct
27 Incorrect 1 ms 468 KB Output isn't correct
28 Correct 1 ms 468 KB Output is correct
29 Incorrect 1 ms 468 KB Output isn't correct
30 Correct 1 ms 468 KB Output is correct
31 Incorrect 1 ms 596 KB Output isn't correct
32 Correct 1 ms 596 KB Output is correct
33 Incorrect 18 ms 6676 KB Output isn't correct
34 Correct 18 ms 6680 KB Output is correct
35 Correct 46 ms 7604 KB Output is correct
36 Incorrect 24 ms 8632 KB Output isn't correct
37 Correct 25 ms 8536 KB Output is correct
38 Correct 78 ms 9852 KB Output is correct
39 Incorrect 29 ms 10784 KB Output isn't correct
40 Correct 29 ms 10828 KB Output is correct
41 Correct 92 ms 12332 KB Output is correct
42 Incorrect 36 ms 13264 KB Output isn't correct
43 Correct 36 ms 13236 KB Output is correct
44 Correct 114 ms 15216 KB Output is correct
45 Incorrect 44 ms 15960 KB Output isn't correct
46 Correct 44 ms 15964 KB Output is correct
47 Correct 146 ms 18448 KB Output is correct
48 Incorrect 51 ms 18960 KB Output isn't correct
49 Correct 52 ms 18912 KB Output is correct
50 Correct 160 ms 21712 KB Output is correct
51 Incorrect 61 ms 22164 KB Output isn't correct
52 Correct 61 ms 22164 KB Output is correct
53 Correct 190 ms 25500 KB Output is correct
54 Incorrect 71 ms 25752 KB Output isn't correct
55 Correct 72 ms 25740 KB Output is correct
56 Correct 252 ms 29540 KB Output is correct
57 Incorrect 79 ms 29488 KB Output isn't correct
58 Correct 80 ms 29600 KB Output is correct
59 Correct 299 ms 33868 KB Output is correct
60 Incorrect 91 ms 33460 KB Output isn't correct
61 Correct 94 ms 33480 KB Output is correct
62 Correct 359 ms 38592 KB Output is correct
63 Correct 244 ms 35448 KB Output is correct
64 Correct 332 ms 35552 KB Output is correct
65 Correct 328 ms 35448 KB Output is correct
66 Incorrect 250 ms 35452 KB Output isn't correct
67 Correct 247 ms 35356 KB Output is correct
68 Correct 171 ms 35392 KB Output is correct
69 Correct 164 ms 35404 KB Output is correct
70 Correct 147 ms 35488 KB Output is correct
71 Correct 150 ms 35532 KB Output is correct
72 Correct 145 ms 35560 KB Output is correct
73 Correct 224 ms 43408 KB Output is correct
74 Correct 247 ms 43556 KB Output is correct
75 Correct 268 ms 43476 KB Output is correct
76 Correct 252 ms 43468 KB Output is correct
77 Correct 256 ms 43436 KB Output is correct
78 Correct 251 ms 43444 KB Output is correct
79 Correct 221 ms 43544 KB Output is correct
80 Correct 228 ms 43464 KB Output is correct
81 Correct 248 ms 43536 KB Output is correct
82 Correct 230 ms 43400 KB Output is correct
83 Correct 303 ms 43292 KB Output is correct
84 Correct 256 ms 43328 KB Output is correct
85 Correct 269 ms 43452 KB Output is correct
86 Correct 277 ms 43388 KB Output is correct
87 Correct 263 ms 43400 KB Output is correct
88 Correct 304 ms 43492 KB Output is correct
89 Correct 327 ms 43532 KB Output is correct
90 Correct 316 ms 43340 KB Output is correct
91 Correct 300 ms 43340 KB Output is correct
92 Correct 287 ms 43340 KB Output is correct