Submission #1105211

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105211		VinhLuu	Railway Trip 2 (JOI22_ho_t4)	C++17	100 / 100	446 ms	126208 KiB

Main

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

const int N = 2e5 + 5;
const int oo = 1e9;

int n, m, k, q, a[N], b[N], _s[N], _t[N];

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 pre(){
  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);
}

namespace sub3{
  int f[N];
  void solve(){
    pre();

    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 AC{
  int kq[N];
  vector<int> Q[N];

  int f[22][N], g[22][N], LG[N], dp[2][18][100005];

  int get_max(int l,int r){
    int k = LG[r - l + 1];
    return max(dp[1][k][l], dp[1][k][r - (1 << k) + 1]);
  }

  struct ST{
    int T[2][N << 1];

    void change(int i,int x,int y){
      i += n - 1;
      T[0][i] = x;
      T[1][i] = y;
      while(i > 1){
        i /= 2;
        T[0][i] = min(T[0][i << 1], T[0][i << 1|1]);
        T[1][i] = max(T[1][i << 1], T[1][i << 1|1]);
      }
    }

    int Min(int l,int r){
      if(l > r) return n + 1;
      r++;
      int ret = n + 1;
      for(l += n - 1, r += n - 1; l < r; l /= 2, r /= 2){
        if(l & 1) ret = min(ret, T[0][l ++]);
        if(r & 1) ret = min(ret, T[0][-- r]);
      }
      return ret;
    }

    int Max(int l,int r){
      if(l > r) return 0;
      r++;
      int ret = 0;
      for(l += n - 1, r += n - 1; l < r; l /= 2, r /= 2){
        if(l & 1) ret = max(ret, T[1][l ++]);
        if(r & 1) ret = max(ret, T[1][-- r]);
      }
      return ret;
    }
  } tree[19];

  int get_min(int l,int r){
    int k = LG[r - l + 1];
    return min(dp[0][k][l], dp[0][k][r - (1 << k) + 1]);
  }

  void solve(){
    pre();

    int pre = 0, nx = 1;

    for(int i = 1; i <= n; i ++){
      LG[i] = (i == 1 ? 0 : LG[i / 2] + 1);
      f[0][i] = le[i], g[0][i] = ri[i];
    }
    // pre/nx - type - log - i

    for(int k = 0; k <= 17; k ++){
      if(k > 0) for(int i = 1; i <= n; i ++){
        f[k][i] = get_min(f[k - 1][i], g[k - 1][i]);
        g[k][i] = get_max(f[k - 1][i], g[k - 1][i]);

//        if(k <= 3) cerr << i << " "  << k << " " << f[k][i] << " " << g[k][i] << " jjj\n";
      }
      for(int i = 1; i <= n; i ++) tree[k].change(i, f[k][i], g[k][i]);
      swap(pre, nx);
      for(int i = n; i >= 1; i --){
        dp[0][0][i] = f[k][i];
        dp[1][0][i] = g[k][i];
        for(int j = 1; j <= 17 && i + (1 << j) - 1 <= n; j ++){
          dp[0][j][i] = min(dp[0][j - 1][i], dp[0][j - 1][i + (1 << (j - 1))]);
          dp[1][j][i] = max(dp[1][j - 1][i], dp[1][j - 1][i + (1 << (j - 1))]);
        }
      }
    }


    for(int t = 1; t <= q; t ++){
      int x = _s[t], y = _t[t];
      int cnt = 0;
      if(f[0][x] <= y && y <= g[0][x]){
        cout << 1 << "\n";
        continue;
      }
      if(f[17][x] > y || g[17][x] < y){
        cout << -1 << "\n";
        continue;
      }
      int l = x, r = x;
      for(int j = 17; j >= 0; j --){
        int _left = tree[j].Min(l, r);
        int _right = tree[j].Max(l, r);
//        cerr << j << " " << j << " " << l << " " << r << " " << _left << " " << _right << " g\n";
        if(_left > y || _right < y){
          cnt += (1 << j);
//          cerr << cnt << " choose\n";
          l = _left, r = _right;
        }
      }
      cout << cnt + 1 << "\n";
    }

  }
}

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];
  AC :: solve();
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:233:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  233 |     freopen(task ".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:234:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  234 |     freopen(task ".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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