제출 #1279933

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1279933		hanguyendanghuy	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	618 ms	223988 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
#define yes cout<<"YES"<<'\n'
#define no cout<<"NO"<<'\n'
#define si size()
#define fi first
#define se second
#define ll long long
#define sr sort
#define pb push_back
const ll MAXN=4e3+5,INF=1e9,MOD=1e9+7;
ll n,m,i,j,k,p,dem,t,sum,ans,dist[MAXN][MAXN],b[4]={0,0,1,-1},c[4]={1,-1,0,0},timego;
string s[MAXN];
void dfs(ll stx,ll sty){
    deque<pair<ll,ll>> q;
    q.pb({stx,sty});
    while(q.size()){
        auto k=q.front();q.pop_front();
        for(ll i=0;i<4;i++){
            ll x=k.fi+b[i],y=k.se+c[i];
            if(s[x][y-1]=='.') continue;
            if(x>0&&y>0&&x<=n&&y<=m&&dist[x][y]>dist[k.fi][k.se]+(s[x][y-1]!=s[k.fi][k.se-1])){
                dist[x][y]=dist[k.fi][k.se]+(s[x][y-1]!=s[k.fi][k.se-1]);
                if(!(s[x][y-1]!=s[k.fi][k.se-1]))q.push_front({x,y});
                else q.pb({x,y});
            }
        }
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(0);
//    freopen("test.INP","r",stdin);
//    freopen("test.OUT","w",stdout);
    cin>>n>>m;
    for(i=1;i<=n;i++){
        cin>>s[i];
        for(j=1;j<=m;j++)
            dist[i][j]=INF;
    }
    dist[1][1]=1;
    dfs(1,1);
    for(i=1;i<=n;i++){
        for(j=1;j<=m;j++){
            if(dist[i][j]==INF) continue;
            ans=max(ans,dist[i][j]);
        }
    }
    cout<<ans;
    return 0;
}

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