oj.uz

Submission #877716

# Submission time Handle Problem Language Result Execution time Memory
877716 2023-11-23T13:10:04 Z asli_bg Tracks in the Snow (BOI13_tracks) C++11
100 / 100
 636 ms 174864 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef pair<int, int> pii;
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define MOD 1000000007
 
const int MAXN=4e3+1;
 
//bool vis[MAXN][MAXN];
 
int grid[MAXN][MAXN];
 
int h,w;
 
int xyon[4]={1,0,-1,0};
int yyon[4]={0,-1,0,1};
 

bool isvalid(int x,int y){
    if(x>=h or x<0 or y>=w or y<0) return false;
    if(grid[x][y]==-1) return false;
    return true;
}

int d[MAXN][MAXN];

int ans=1;
 
void bfs(int x,int y){
    deque<pii> q;
    q.push_back({x,y});
    //vis[x][y]=true;
    d[x][y]=1;
 
    while(q.size()){
        auto el=q.front();
        q.pop_front();

        ans=max(ans,d[el.fi][el.se]);
 
        for(int i=0;i<4;i++){
            int newx=el.fi+xyon[i];
            int newy=el.se+yyon[i];
 
            if(isvalid(newx,newy) and d[newx][newy]==0){
                //vis[newx][newy]=true;

                if(grid[newx][newy]==grid[el.fi][el.se]){
                    d[newx][newy]=d[el.fi][el.se];
                    q.push_front({newx,newy});
                }
                else{
                    d[newx][newy]=d[el.fi][el.se]+1;
                    q.push_back({newx,newy});
                }
                //cout<<"distance of "<<newx<<'-'<<newy<<" is: "<<d[newx][newy]<<endl;
            }
 
        }

        //grid[el.fi][el.se]=!grid[el.fi][el.se];
    }
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); 
 
    cin>>h>>w;
 
    map<char,int> anim;
    anim['F']=1;
    anim['R']=0;
    anim['.']=-1;

    //cout<<d[0][2]<<endl;
 
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            char c;
            cin>>c;
            grid[i][j]=anim[c];
        }
    }
 
    bfs(0,0);
    cout<<ans<<endl;
    //cout<<d[h][w]<<endl;
 
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 13656 KB Output is correct
2 Correct 0 ms 2396 KB Output is correct
3 Correct 1 ms 2648 KB Output is correct
4 Correct 8 ms 13572 KB Output is correct
5 Correct 3 ms 8024 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2652 KB Output is correct
8 Correct 1 ms 2648 KB Output is correct
9 Correct 1 ms 4952 KB Output is correct
10 Correct 3 ms 7512 KB Output is correct
11 Correct 2 ms 5464 KB Output is correct
12 Correct 5 ms 8044 KB Output is correct
13 Correct 4 ms 8028 KB Output is correct
14 Correct 3 ms 8028 KB Output is correct
15 Correct 12 ms 13656 KB Output is correct
16 Correct 13 ms 13660 KB Output is correct
17 Correct 11 ms 13404 KB Output is correct
18 Correct 8 ms 13404 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 77404 KB Output is correct
2 Correct 51 ms 29268 KB Output is correct
3 Correct 312 ms 104924 KB Output is correct
4 Correct 101 ms 52696 KB Output is correct
5 Correct 192 ms 82100 KB Output is correct
6 Correct 624 ms 139472 KB Output is correct
7 Correct 15 ms 78364 KB Output is correct
8 Correct 14 ms 77404 KB Output is correct
9 Correct 2 ms 2720 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 19 ms 77916 KB Output is correct
12 Correct 2 ms 5212 KB Output is correct
13 Correct 56 ms 29268 KB Output is correct
14 Correct 29 ms 22364 KB Output is correct
15 Correct 28 ms 26716 KB Output is correct
16 Correct 23 ms 12296 KB Output is correct
17 Correct 125 ms 53584 KB Output is correct
18 Correct 103 ms 56860 KB Output is correct
19 Correct 96 ms 52308 KB Output is correct
20 Correct 79 ms 47328 KB Output is correct
21 Correct 195 ms 82988 KB Output is correct
22 Correct 188 ms 82004 KB Output is correct
23 Correct 233 ms 67668 KB Output is correct
24 Correct 197 ms 89468 KB Output is correct
25 Correct 504 ms 125520 KB Output is correct
26 Correct 358 ms 174864 KB Output is correct
27 Correct 485 ms 170752 KB Output is correct
28 Correct 611 ms 139212 KB Output is correct
29 Correct 636 ms 137296 KB Output is correct
30 Correct 574 ms 159268 KB Output is correct
31 Correct 521 ms 112212 KB Output is correct
32 Correct 442 ms 159584 KB Output is correct