Submission #985178

#	Time	Username	Problem	Language	Result	Execution time	Memory
985178		Tsagana	Sequence (APIO23_sequence)	C++17	100 / 100	763 ms	77916 KiB

sequence

#include "sequence.h"
#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define f first
#define s second
 
vector<int> ct[500005];
int N;
 
struct segTree {
  pii seg[4*500005];
  int lazy[4*500005];
 
  void laze(int i, int l, int r) {
    if(lazy[i]) {
      seg[i] = {seg[i].f+lazy[i], seg[i].s+lazy[i]};
      if(l!=r) {
        lazy[i*2+1] += lazy[i];
        lazy[i*2+2] += lazy[i];
      }
      lazy[i] = 0;
    }
  }
 
  void build(int i, int l, int r, int val) {
    lazy[i] = 0;
    if(l==r) {
      seg[i].f = seg[i].s = val*(l);
      return;
    }
    int m = (l+r)/2;
    build(i*2+1, l, m, val);
    build(i*2+2, m+1, r, val);
    seg[i].f = min(seg[i*2+1].f, seg[i*2+2].f);
    seg[i].s = max(seg[i*2+1].s, seg[i*2+2].s);
  }
  void build(int val) {
    build(0, 0, N, val);
  }
 
  void update(int i, int l, int r, int wl, int wr, int val) {
    if(wl<=l && wr>=r) lazy[i] += val;
    laze(i, l, r);
    if(wl>r || wr<l || (wl<=l && wr>=r)) return;
    int m = (l+r)/2;
    update(i*2+1, l, m, wl, wr, val);
    update(i*2+2, m+1, r, wl, wr, val);
    seg[i].f = min(seg[i*2+1].f, seg[i*2+2].f);
    seg[i].s = max(seg[i*2+1].s, seg[i*2+2].s);
  }
  void update(int wl, int wr, int val) {
    update(0, 0, N, wl+1, wr+1, val);
  }
 
  pii query(int i, int l, int r, int wl, int wr) {
    laze(i, l, r);
    if(wl>r || wr<l) return {(int)1e9, (int)-1e9};
    if(wl<=l && wr>=r) return seg[i];
    int m = (l+r)/2;
    pii q1 = query(i*2+1, l, m, wl, wr);
    pii q2 = query(i*2+2, m+1, r, wl, wr);
    return {min(q1.f, q2.f), max(q1.s, q2.s)};
  }
  pii query(int wl, int wr) {
    return query(0, 0, N, wl+1, wr+1);
  }
} les, mor;
 
int sequence(int n, std::vector<int> A) {
  N = n;
  for(int i=0;i<N;i++) {
    ct[A[i]].push_back(i);
  }
  int ans = 1;
  les.build(-1);
  mor.build(1);
  for(int i=1;i<=N;i++) {
    for(int j:ct[i]) {
      les.update(j, N-1, 2);
    }
    for(int j=0;j+ans<ct[i].size();j++) {
      int st = ct[i][j];
      int en = ct[i][j+ans];
      int qles = les.query(en, N-1).s - les.query(-1, st-1).f;
      int qmor = mor.query(en, N-1).s - mor.query(-1, st-1).f;
      if(qles>=0 && qmor>=0) {
        ans++; j--;
      }
    }
    for(int j:ct[i]) {
      mor.update(j, N-1, -2);
    }
  }
  return ans;
}

Compilation message (stderr)

sequence.cpp: In function 'int sequence(int, std::vector<int>)':
sequence.cpp:82:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |     for(int j=0;j+ans<ct[i].size();j++) {
      |                 ~~~~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 7 / 7
• Subtask 4: 12 / 12
• Subtask 5: 13 / 13
• Subtask 6: 22 / 22
• Subtask 7: 18 / 18