Submission #1019201

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019201		Luvidi	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	655 ms	158784 KiB

tracks

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

#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fs first
#define sc second
#define pb push_back

void solve() {
    int n,m;
    cin>>n>>m;
    int a[n][m];
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            char c;
            cin>>c;
            if(c=='F')a[i][j]=0;
            else if(c=='R')a[i][j]=1;
            else a[i][j]=-1;
        }
    }
    int dist[n][m],dx[4]={-1,1,0,0},dy[4]={0,0,-1,1},ans=0;
    memset(dist,-1,sizeof(dist));
    deque<pii> dq;
    dist[0][0]=0;
    dq.push_back({0,0});
    while(!dq.empty()){
        auto[r,c]=dq.front();
        dq.pop_front();
        for(int i=0;i<4;i++){
            int r2=r+dx[i],c2=c+dy[i];
            if(r2>=0&&c2>=0&&r2<n&&c2<m){
                if(a[r2][c2]==-1||dist[r2][c2]!=-1)continue; 
                if(a[r2][c2]==a[r][c]){
                    dist[r2][c2]=dist[r][c];
                    dq.push_front({r2,c2});
                }else{
                    dist[r2][c2]=dist[r][c]+1;
                    ans=max(ans,dist[r2][c2]);
                    dq.push_back({r2,c2});
                }
            }
        }
        a[r][c]=-1;
    }
    cout<<ans+1;
}

int main() {   
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    solve();
}

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