Submission #742461

#	Time	Username	Problem	Language	Result	Execution time	Memory
742461		irmuun	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	468 ms	113156 KiB

tracks

#include<bits/stdc++.h>
 
using namespace std;
 
#define pb push_back
#define ll long long
#define ff first
#define ss second
#define all(s) s.begin(),s.end()

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int h,w;
    cin>>h>>w;
    string s[h+5];
    int used[h+5][w+5];
    for(int i=0;i<h;i++){
        cin>>s[i];
        for(int j=0;j<w;j++){
            used[i][j]=0;
        }
    }
    used[0][0]=1;
    deque<pair<int,int>>q;
    q.pb({0,0});
    int ans=0;
    while(!q.empty()){
        int x=q.front().ff,y=q.front().ss;
        ans=max(ans,used[x][y]);
        q.pop_front();
        if(x>0&&used[x-1][y]==0&&s[x-1][y]!='.'){
            if(s[x-1][y]==s[x][y]){
                used[x-1][y]=used[x][y];
                q.push_front({x-1,y});
            }
            else{
                used[x-1][y]=used[x][y]+1;
                q.pb({x-1,y});
            }
        }
        if(x<h-1&&used[x+1][y]==0&&s[x+1][y]!='.'){
            if(s[x+1][y]==s[x][y]){
                used[x+1][y]=used[x][y];
                q.push_front({x+1,y});
            }
            else{
                used[x+1][y]=used[x][y]+1;
                q.pb({x+1,y});
            }
        }
        if(y>0&&used[x][y-1]==0&&s[x][y-1]!='.'){
            if(s[x][y-1]==s[x][y]){
                used[x][y-1]=used[x][y];
                q.push_front({x,y-1});
            }
            else{
                used[x][y-1]=used[x][y]+1;
                q.pb({x,y-1});
            }
        }
        if(y<w-1&&used[x][y+1]==0&&s[x][y+1]!='.'){
            if(s[x][y+1]==s[x][y]){
                used[x][y+1]=used[x][y];
                q.push_front({x,y+1});
            }
            else{
                used[x][y+1]=used[x][y]+1;
                q.pb({x,y+1});
            }
        }
    }
    cout<<ans;
}

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