Submission #865605

#	Time	Username	Problem	Language	Result	Execution time	Memory
865605		mychecksedad	Abracadabra (CEOI22_abracadabra)	C++17	100 / 100	422 ms	52912 KiB

Main

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;


int n, q, ans[N], T[N], to[N], posarray[N];
array<int, 2> pos[N];
vector<array<int, 3>> Q;
vector<int> a;
vector<bool> active;
void build(int l, int r, int k){
  if(l == r){
    if(active[l])
      T[k] = pos[l][1] - pos[l][0] + 1;
    else
      T[k] = 0;
    return;
  }
  int m = l+r>>1;
  build(l, m, k<<1);
  build(m+1, r, k<<1|1);
  T[k] = T[k<<1] + T[k<<1|1];
}
array<int, 4> get(int l, int r, int p, int k){
  if(l == r){
    return {l, a[pos[l][0] + p - 1], pos[l][1] - pos[l][0] + 1, pos[l][1] - pos[l][0] + 1 - p + 1};
  }
  int m = l+r>>1;
  if(T[k<<1] >= p){
    return get(l, m, p, k<<1);
  }
  return get(m+1, r, p - T[k<<1], k<<1|1);
}

void update(int l, int r, int p, int k, int val){
  if(l == r){
    T[k] = val;
    pos[l] = {posarray[l], posarray[l] + val - 1};
    return;
  }
  int m = l+r>>1;
  if(p <= m)
    update(l, m, p, k<<1, val);
  else
    update(m+1, r, p, k<<1|1, val);
  T[k] = T[k<<1] + T[k<<1|1];
}



void solve(){
  cin >> n >> q;
  a.resize(n);
  active.resize(n+1);
  for(int i = 0; i < n; ++i) cin >> a[i];
  for(int i = 0; i < q; ++i){
    int t, x; cin >> t  >> x;
    Q.pb({t, x, i});
  }
  for(int i = 0; i < n; ++i) posarray[a[i]] = i; 
  to[n - 1] = n - 1;
  deque<int> qq;
  qq.pb(n - 1);
  for(int i = n - 2; i >= 0; --i){
    while(!qq.empty() && a[qq.back()] < a[i]) qq.pop_back();
    if(qq.empty()) to[i] = n-1;
    else to[i] = qq.back()-1;
    qq.pb(i);
  }
  sort(all(Q));
  bool ok = 1;
  int t = 0;
  int qp = 0;
  while(qp < Q.size() && Q[qp][0] == t){
    ans[Q[qp][2]] = a[Q[qp][1] - 1];
    ++qp;
  }
  int last = a[0], lastpos = 0;
  for(int i = 0; i < n/2; ++i){
    if(last < a[i]){
      pos[a[lastpos]] = {lastpos, i - 1};
      active[a[lastpos]] = 1;
      last = a[i], lastpos = i;
    }
  }
  active[a[lastpos]] = 1;
  pos[a[lastpos]] = {lastpos, n/2-1};

  last = a[n/2], lastpos = n/2;
  for(int i = n/2; i < n; ++i){
    if(last < a[i]){
      pos[a[lastpos]] = {lastpos, i - 1};
      active[a[lastpos]] = 1;
      last = a[i], lastpos = i;
    }
  }
  active[a[lastpos]] = 1;
  pos[a[lastpos]] = {lastpos, n-1};

  build(1, n, 1);
  while(ok){
    ++t;
    while(qp < Q.size() && (Q[qp][0] == t || !ok)){
      ans[Q[qp][2]] = get(1, n, Q[qp][1], 1)[1];
      ++qp;
    }
    ok = 0;
    auto x = get(1, n, n/2+1, 1);
    int lenn = x[2];
    while(x[0] > x[1]){
      // cout << x[0] << ' ' << x[1] << ' '  << x[2] << ' ' << x[3] << '\n';
      ok = 1;
      int len = min(to[posarray[x[1]]] - posarray[x[1]] + 1, x[3]);
      lenn -= len;
      update(1, n, x[0], 1, lenn);
      update(1, n, x[1], 1, len);
      if(x[3] - len > 0)
        x = {x[0], a[posarray[x[1]] + len], lenn, x[3] - len};
      else
        break;
    }
  }
  while(qp < Q.size()){
    ans[Q[qp][2]] = get(1, n, Q[qp][1], 1)[1];
    ++qp;
  }

  for(int i = 0; i < q; ++i) cout << ans[i] << '\n';
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

Compilation message (stderr)

Main.cpp: In function 'void build(int, int, int)':
Main.cpp:26:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   26 |   int m = l+r>>1;
      |           ~^~
Main.cpp: In function 'std::array<int, 4> get(int, int, int, int)':
Main.cpp:35:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   35 |   int m = l+r>>1;
      |           ~^~
Main.cpp: In function 'void update(int, int, int, int, int)':
Main.cpp:48:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   48 |   int m = l+r>>1;
      |           ~^~
Main.cpp: In function 'void solve()':
Main.cpp:81:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |   while(qp < Q.size() && Q[qp][0] == t){
      |         ~~~^~~~~~~~~~
Main.cpp:110:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  110 |     while(qp < Q.size() && (Q[qp][0] == t || !ok)){
      |           ~~~^~~~~~~~~~
Main.cpp:130:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  130 |   while(qp < Q.size()){
      |         ~~~^~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:141:15: warning: unused variable 'aa' [-Wunused-variable]
  141 |   int tt = 1, aa;
      |               ^~

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25