Submission #1107902

#	Time	Username	Problem	Language	Result	Execution time	Memory
1107902		0pt1mus23	Tracks in the Snow (BOI13_tracks)	C++14	0 / 100	1461 ms	267608 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
#define int long long int
#define ins insert      
#define pb push_back
#define endl '\n'
#define putr(x) cout<<x<<endl;return; 
#define all(x) x.begin(),x.end()
const int mod = 1e9 +7, sze = 1e5 +5, inf = INT_MAX, LL = 30;

int comp[4005][4005];
int used[4005][4005];
const int dx[4] = {-1,1,0,0};
const int dy[4] = {0,0,-1,1};
void rush(){
    int n,m;
    cin>>n>>m;
 
    vector<vector<char>> arr(n,vector<char>(m));
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            cin>>arr[i][j];
            comp[i][j]=-1;
        }
    }
    int ans=0;
    queue<pair<pair<int,int>,int>> q;
    q.push({{0,0},1});
    comp[0][0]=1;
    int cnt=1;
    while(!q.empty()){
        auto node = q.front();
        q.pop();
        if(used[node.first.first][node.first.second]){
            continue;
        }
        ans=max(ans,node.second);
        used[node.first.first][node.first.second]=1;
        for(int i=0;i<4;i++){
            int a = node.first.first + dx[i];
            int b = node.first.second + dy[i];

            if(a>=0 && a<n && b>=0 && b<m){
                if(arr[a][b]!='.'){
                    if(!comp[a][b]){
                        if(arr[a][b]==arr[node.first.first][node.first.second]){
                            comp[a][b]= comp[node.first.first][node.first.second]; 
                        }
                        else{
                            comp[a][b]=++cnt;
                        }
                    }
                    if(comp[a][b]!=comp[node.first.first][node.first.second]){
                        q.push({{a,b}, node.second +1});
                    }
                    else{
                        q.push({{a,b}, node.second});
                    }
                }
                else{
                    q.push({{a,b},node.second});
                }

            }
        }

    }
    putr(ans);
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int tt = 1; 
    // cin>>tt;

    while(tt--){
        rush();
    }

    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 70