제출 #520304

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
520304		PikaQ	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	1118 ms	194988 KiB

tracks

#include<bits/stdc++.h>
// #define int ll
#define forn(i,n) for(int i=0;i<(n);i++)
#define Forn(i,n) for(int i=1;i<=(n);i++)
#define For(i, a, b) for (int i = a; i <= b; i++)
#define foR(i, a, b) for (int i = a; i >= b; i--)
#define ll long long
#define pb push_back
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define vi vector<int>
#define vl vector<long long>
#define vpi vector<pair<int,int> >
#define pii pair<int,int>
#define pll pair<long long,long long>
#define mp make_pair
#define all(p) p.begin(),p.end()
#define alr(p,q) p+1,p+q+1
#define ull unsigned long long
#define st0(p) memset((p),0,sizeof(p))
#define T(x) ((x)%2 ? s[(x)/2] : '.')
#define lowb(x) x&-x
#define sz(x) (x).size()
#define rz resize
#define printv(x) {for(auto &i : x) {cout << i << ' ';}cout <<'\n';}
using namespace std;
 
inline void USACO(string filename){
  freopen((filename+".in").c_str(),"r",stdin);
  freopen((filename+".out").c_str(),"w",stdout);
}
 
void debug() {cout << endl;}
template <class T, class ...U> void debug(T a, U ... b) { cout << a << " "; debug(b...);}
// template <class T> int max(T a, T ... b) { cout << a << " "; debug(b...);}
const int INF = 1e9+7;
const int mod = 1e9+7;
const int N = 4e3+9;
const int C = 35;
const double eps = 1e-7;

int n,m;
int d[N][N];
char c[N][N];

int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
bool vis[N][N];


bool inside(int x,int y){
  return !(x < 0 || y < 0 || x >= n || y >= m || c[x][y] == '.');
}

void solve(){
  cin >> n >> m;
  forn(i,n) forn(j,m) cin >> c[i][j];
  deque<pii> dq;
  dq.pb({0,0});
  int ans = 0;
  while(!dq.empty()){
    pii cur = dq.front();dq.pop_front();
    vis[cur.F][cur.S] = 1;
    forn(i,4){
      int nx = cur.F + dx[i],ny = cur.S + dy[i];
      if(inside(nx,ny) && !vis[nx][ny] ){
        // debug(nx,ny);
        if(c[nx][ny] == c[cur.F][cur.S]) {
          d[nx][ny] = d[cur.F][cur.S];
          dq.push_front({nx,ny});
        }else{
          d[nx][ny] = d[cur.F][cur.S] +1;
          dq.push_back({nx,ny});
        }
      }
    }
    ans = max(ans,d[cur.F][cur.S]);
  }
  cout << ans+1 << '\n';
}   

signed main(){
  // USACO("248");
  cin.tie(0);
  cout.tie(0);
  ios_base::sync_with_stdio(0);

  // cout << "?";
    // cout << fixed << setprecision(15);
    solve();
  return 0;
}

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