Submission #1104901

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104901		VinhLuu	Railway Trip 2 (JOI22_ho_t4)	C++17	27 / 100	2078 ms	28096 KiB

Main

#include <bits/stdc++.h>
//#define int long long
#define ll long long
using namespace std;

const int N = 1e6 + 5;
const int oo = 1e9;

int n, m, k, q, a[N], b[N], S[N], T[N];

namespace sub3{
  int le[N], ri[N], f[N];

  int st[2][N << 2];

  void build(int i,int l,int r){
    if(l == r){
      st[0][i] = st[1][i] = l;
      return;
    }
    int mid = (l + r) / 2;
    build(i << 1, l, mid);
    build(i << 1|1, mid + 1, r);
    st[0][i] = n + 1;
    st[1][i] = 0;
  }

  void dolz(int i){
    if(st[0][i] != n + 1){
      int x = st[0][i]; st[0][i] = n + 1;
      st[0][i << 1] = min(st[0][i << 1], x);
      st[0][i << 1|1] = min(st[0][i << 1|1], x);
    }
    if(st[1][i] != 0){
      int x = st[1][i]; st[1][i] = 0;
      st[1][i << 1] = max(st[1][i << 1], x);
      st[1][i << 1|1] = max(st[1][i << 1|1], x);
    }
  }

  void update(int i,int l,int r,int u,int v,int val,int type){
    if(l > r || r < u || v < l) return;
    if(u <= l && r <= v){
      if(!type) st[0][i] = min(st[0][i], val);
      else st[1][i] = max(st[1][i], val);
      return;
    }
    dolz(i);
    int mid = (l + r) / 2;
    update(i << 1, l, mid, u, v, val, type);
    update(i << 1|1, mid + 1, r, u, v, val, type);
  }

  void done(int i,int l,int r){
    if(l == r){
      le[l] = st[0][i];
      ri[l] = st[1][i];
      return;
    }
    dolz(i);
    int mid = (l + r) / 2;
    done(i << 1, l, mid);
    done(i << 1|1, mid + 1, r);
  }

  void solve(){
    build(1, 1, n);
    for(int i = 1; i <= m; i ++){
      if(a[i] < b[i]){
        update(1, 1, n, a[i], min(a[i] + k - 1, b[i] - 1), b[i], 1);
      }else update(1, 1, n, max(a[i] - k + 1, b[i] + 1), a[i], b[i], 0);
    }
    done(1, 1, n);

    for(int k = 1; k <= q; k ++){
      int x = S[k], y = T[k];
      queue<int> q;
      for(int i = 1; i <= n; i ++) f[i] = oo;
      for(int i = le[x]; i <= ri[x]; i ++){
        f[i] = 1;
        q.push(i);
      }
      int pl = le[x], pr = ri[x];
      f[x] = 0;
      while(!q.empty()){
        int u = q.front(); q.pop();
        if(le[u] < pl){
          for(int i = le[u]; i <= pl - 1; i ++){
            f[i] = f[u] + 1;
            q.push(i);
          }
          pl = le[u];
        }
        if(ri[u] > pr){
          for(int i = pr + 1; i <= ri[u]; i ++){
            f[i] = f[u] + 1;
            q.push(i);
          }
          pr = ri[u];
        }
      }
      if(f[y] == oo){
        cout << -1 << "\n";
        continue;
      }else cout << f[y] << "\n";
    }
  }
}

//namespace sub5{
//
//}

signed main(){
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #define task "v"
  if(fopen(task ".inp","r")){
    freopen(task ".inp","r",stdin);
    freopen(task ".out","w",stdout);
  }
  cin >> n >> k >> m;
  for(int i = 1; i <= m; i ++) cin >> a[i] >> b[i];
  cin >> q;
  for(int i = 1; i <= q; i ++) cin >> S[i] >> T[i];
  sub3 :: solve();
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:118:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |     freopen(task ".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:119:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  119 |     freopen(task ".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 0 / 25
• Subtask 5: 0 / 35
• Subtask 6: 0 / 13