Submission #1224830

#	Time	Username	Problem	Language	Result	Execution time	Memory
1224830		shivam	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	531 ms	110892 KiB

tracks

#include<bits/stdc++.h>
using namespace std;


int dx[4] = {0,0,1,-1};
int dy[4] = {1,-1,0,0};

const int inf = 1e9+7;

void solve(){
    int h,w ;
    cin >> h >> w ;
    vector<string>v(h+1) ;
    vector<vector<int>>dist(h+1,vector<int>(w+1,inf)) ;
    for(int i=1;i<=h;i++){
        string s;
        cin>>s;
        v[i] = " " + s;
    }
    deque<pair<int,int>>q;
    q.push_back({1,1});
    dist[1][1] = 0;
    while(!q.empty()){
        auto pp = q.front();
        q.pop_front();
        int x = pp.first;
        int y = pp.second;
        char cur = v[x][y];
        for(int i=0;i<4;i++){
            int nx = x+dx[i];
            int ny = y+dy[i];
            if(nx<1 || nx>h || ny<1 || ny>w)continue;
            if(v[nx][ny] == cur && dist[nx][ny] > dist[x][y]){
                dist[nx][ny] = dist[x][y];
                q.push_front({nx,ny});
            }
            else if(v[nx][ny] == (cur^'F'^'R') &&  dist[nx][ny] > dist[x][y] + 1){
                dist[nx][ny] = dist[x][y] + 1;
                q.push_back({nx,ny});
            }
        }
    }
    int ans =0;
    for(int i=1;i<=h;i++){
        for(int j=1;j<=w;j++){
            if(dist[i][j] != inf){
                ans= max(ans,dist[i][j]);
            }
        }
    }
    cout << ans+1 << "\n";
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t=1;
    // cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70