Submission #541824

#	Time	Username	Problem	Language	Result	Execution time	Memory
541824		codebuster_10	Tracks in the Snow (BOI13_tracks)	C++17	0 / 100	585 ms	228296 KiB

tracks

#include <bits/stdc++.h>
#define int int64_t //be careful about this 

using namespace std;

#define vt vector 
#define ar array 
#define pr pair 

#define f first 
#define s second

#define pb push_back
#define eb emplace_back

#define fr(i,a,b) for(int i = a; i < b; ++i)
#define rf(i,a,b) for(int i = a-1; i >= b; --i)
#define all(x) x.begin(),x.end()
#define mem(a,b) memset(a,b,sizeof(a))


using VI = vector<int>;
using VVI = vector<vector<int>>;

namespace IN{
  template<class T> void re(vector<T> &A);
  template<class S,class T> void re(pair<S,T> &A);
  template<class T,size_t N> void re(array<T,N> &A);

  template<class T> void re(T& x){ 
    cin >> x;}
  template<class H, class... T> void re(H& h, T&... t){ 
    re(h); re(t...);}

  template<class T> void re(vector<T> &A){ 
    for(auto& x : A) re(x);}
  template<class S,class T> void re(pair<S,T> &A){ 
      re(A.first); re(A.second);}
  template<class T,size_t N> void re(array<T,N> &A){
    for(int i = 0; i < N; ++i)  re(A[i]);}
}

namespace OUT{
  template<class T>
  void __p(const T& a){ cout<<a; }
  template<class T, class F>
  void __p(const pair<T, F>& a){ cout<<"{"; __p(a.first); cout<<","; __p(a.second); cout<<"}\n"; }
  template<class T, size_t N>
  void __p(const array<T,N>& a){ cout<<"{"; for(int i=0;i<N;++i)__p(a[i]),cout<<",}\n"[i+1==N]; }
  template<class T>
  void __p(const vector<T>& a){
    cout<<"{";for(auto it=a.begin();it<a.end();it++)__p(*it),cout<<",}\n"[it+1==a.end()]; }
  template<class T, class ...Arg>
  void __p(T a1, Arg ...a){__p(a1); __p(a...); }
  template<class Arg1>
  void __f(const char *s, Arg1 &&arg1){ cout<<s<<" : "; __p(arg1); cout<<endl; }
  template<class Arg1, class ... Args>
  void __f(const char *ss, Arg1 &&arg1, Args &&... args){
    int b=0,i=0; do{ if(ss[i]=='(') b++; if(ss[i]==')') b--; i++;}while(!(ss[i]==','&&b==0));
    const char *comma=ss+i; cout.write(ss,comma-ss)<<" : ";__p(arg1);cout<<" | ";__f(comma+1,args...);}
  #define trace(...) cout<<"Line:"<<__LINE__<<"  ", __f(#__VA_ARGS__, __VA_ARGS__)
}


namespace FUN{
  void IO(string s = ""){
    ios_base::sync_with_stdio(NULL); 
    cin.tie(nullptr); 
    cout.precision(20); 
    cout << fixed;
    if(!s.empty()){
      freopen((s+".in").c_str(),"r",stdin);
      freopen((s+".out").c_str(),"w",stdout);
    }
  }

  const auto start_time = chrono::high_resolution_clock::now();
  void output_run_time(){
    // will work for ac,cc&&cf.
#ifndef ONLINE_JUDGE
    auto end_time = chrono::high_resolution_clock::now();
    chrono::duration<double> diff = end_time-start_time;
      cout << "\n\n\nTime Taken : " << diff.count();
#endif
  }

  template<class T> bool ckmin(T& a, const T& b){ 
    return b < a ? a = b, true : false; }
    
  template<class T> bool ckmax(T& a, const T& b){ 
    return a < b ? a = b, true : false; }

  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
  int my_rand(int L, int R){ 
    return uniform_int_distribution<int>(L,R)(rng); }
  
  template<class T> int sz(const T& x){ 
    return int(x.size()); }

  template<class T> int lb(const vector<T>& vec,const T& val){
    return int(lower_bound(vec.begin(), vec.end(),val) - vec.begin()); }

  template<class T> int ub(const vector<T>& vec,const T& val){
    return int(upper_bound(vec.begin(), vec.end(),val) - vec.begin()); }

  constexpr int  dx[4] = {1,0,-1,0};
  constexpr int  dy[4] = {0,1,0,-1};

  constexpr long long INFLL1 = 1e16, INFLL2 = 9e18;
  constexpr int INF = 2e9;
}


using namespace IN;
using namespace OUT;
using namespace FUN;
























signed main(){
  IO();

  int n,m;
  re(n,m);

  vector<string> a(n);
  re(a);

  if(a[0][0] == '.'){
    cout << 0;
    return 0;
  }

  VVI dis(n,VI (m,INF));

  bool vis[n][m];
  mem(vis,0);

  int ans = 1;

  deque<pair<int,int>> q;
  q.push_back({0,0});
  vis[0][0] = 1;
  dis[0][0] = 1;

  while(!q.empty()){
    auto [i,j] = q.front(); q.pop_front();
    fr(k,0,4){
      int ni = i + dx[k], nj = j + dy[k];
      if(ni >= 0 && ni < n && nj >= 0 && nj < m && a[ni][nj] != '.' && !vis[ni][nj]){
        if(a[ni][nj] == a[i][j]){
          dis[ni][nj] = dis[i][j];
          vis[ni][nj] = 1;
          q.push_front({ni,nj});
        }else{
          dis[ni][nj] = dis[i][j] + 1;
          ckmax(ans,dis[ni][nj]);
          vis[ni][nj] = 1;
          q.push_back({ni,nj});
        }
      }
    }
  }

  cout << ans;

  output_run_time();
  return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void FUN::IO(std::string)':
tracks.cpp:72:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |       freopen((s+".in").c_str(),"r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:73:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |       freopen((s+".out").c_str(),"w",stdout);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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