Submission #1185500

#	Time	Username	Problem	Language	Result	Execution time	Memory
1185500		Vivek_03_	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	496 ms	112156 KiB

tracks

#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<set>
#include<map>
#include<deque>
#include<unordered_map>
#include<cstdio>
using namespace std;
 
#ifndef LOCAL
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx2,popcnt")
#endif
 
#define fastio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define pb push_back
#define ppb pop_back
#define mp make_pair
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double lld;
 
#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _print(x); cerr << endl;
#else
#define debug(x)
#endif
 
void _print(ll t) {cerr << t;}
void _print(int t) {cerr << t;}
void _print(string t) {cerr << t;}
void _print(char t) {cerr << t;}
void _print(lld t) {cerr << t;}
void _print(double t) {cerr << t;}
void _print(ull t) {cerr << t;}
void _print(pair<int,int> t) {cerr << t.first << ' '<<t.second;}
 
template <class T> void _print(vector <T> v);
template <class T> void _print(set <T> v);
template <class T> void _print(multiset <T> v);
template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
 
int main()
{
    fastio();
 
    #ifndef ONLINE_JUDGE
        freopen("Error.txt", "w", stderr);
    #endif
    
    int n,m;
    cin>>n>>m;

    vector<string> v(n);

    for(int i=0;i<n;i++)
    {
        cin>>v[i];
    }

    vector<vector<int>> dist(n, vector<int>(m,1e9));
    vector<int> di = {1,0,-1,0,1};

    dist[0][0] = 1;

    deque<pair<int,int>> dq;
    dq.push_back({0,0});

    int ans = 1;
    while(!dq.empty())
    {
        int x = dq.front().first, y = dq.front().second;
        dq.pop_front();

        ans = max(ans, dist[x][y]);

        for(int i=0;i<4;i++)
        {
            int nx = x + di[i], ny = y + di[i+1];

            if(nx<0 || ny<0 || nx>=n || ny>=m || v[nx][ny]=='.') continue;
            
            int wt = (v[x][y] != v[nx][ny]);

            if(dist[x][y] + wt < dist[nx][ny])
            {
                dist[nx][ny] = dist[x][y] + wt;

                if(wt) dq.push_back({nx,ny});
                else dq.push_front({nx,ny});
            }
        }
    }
    cout<<ans<<'\n';
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:56:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         freopen("Error.txt", "w", stderr);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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