Submission #346240

#TimeUsernameProblemLanguageResultExecution timeMemory
346240casperwangDancing Elephants (IOI11_elephants)C++14
Compilation error
0 ms0 KiB
#include "elephants.h"
#include <bits/stdc++.h>
#define pb push_back
#define All(x) x.begin(), x.end()
#define pii pair<int,int>
#define ff first
#define ss second
using namespace std;
#define debug(args...) kout("[ " + string(#args) + " ]", args)
void kout() { cerr << endl; }
template <class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ',kout(b...); }
template <class T> void pary(T L, T R) { while (L != R) cerr << *L << " \n"[++L==R]; }

const int MAXN = 150000;
const int K = 300;
int n, m, seg;
int cnt;
vector <pii> a;
vector <vector<pii>> B;
vector <pii> rng;
vector <int> pos;
vector <pii> info;

void build_block(int id, bool flag) {
  int len = B[id].size();
  if (flag) sort(All(B[id]));
  for (int i = len-1; i >= 0; i--) {
    pos[B[id][i].ss] = id;
    if (B[id][i].ff + seg >= B[id][len-1].ff) {
      info[B[id][i].ss] = pii(1, B[id][i].ff + seg);
      continue;
    }
    auto it = upper_bound(All(B[id]), pii(B[id][i].ff + seg, n));
    info[B[id][i].ss] = pii(info[it->ss].ff + 1, info[it->ss].ss);
  }
  if (len) {
    rng[id] = pii(B[id][0].ff, B[id][len-1].ff);
  } else {
    rng[id] = pii(id==0 ? -INF : rng[id-1].ss, id==m-1 ? INF, rng[id+1].ff);
  }
}

void build() {
  sort(All(a));
  for (int i = 0; i < m; i++)
    B[i].clear();
  for (int i = 0; i < n; i++)
    B[i/K].pb(a[i]);
  for (int i = 0; i < m; i++)
    build_block(i, false);
  sort(All(a), [](const pii x, const pii y) {
    return x.ss < y.ss;
  });
}

int solve() {
  int ans = 0, now = -1;
  for (int i = 0; i < m; i++) {
    auto tmp = upper_bound(All(B[i]), pii(now, n+1));
    if (tmp == B[i].end()) continue;
    ans += info[tmp->ss].ff;
    now = info[tmp->ss].ss;
  }
  return ans;
}

void init(int N, int L, int X[]) {
  cnt = 0;
  srand(time(NULL));
  n = N, m = (n-1)/K+1, seg = L;
  a.clear(), a.resize(n);
  pos.clear(), pos.resize(n);
  info.clear(), info.resize(n);
  B.clear(), B.resize(m);
  rng.clear(), rng.resize(m);
  for (int i = 0; i < n; i++)
    a[i].ff = X[i], a[i].ss = i;
  build();
  solve();
}

int update(int i, int y) {
  cnt++;
  a[i].ff = y;
  if (cnt % K == 0) build();
  int id = pos[i];
  for (int j = 0; j < (int)B[id].size(); j++)
    if (B[id][j].ss == i) B[id].erase(B[id].begin()+j);
  build_block(id, false);
  pos[i] = -1;
  vector <int> ran(m);
  for (int j = 0; j < m; j++) ran[j] = j;
  random_shuffle(All(ran));
  for (int j : ran) {
    if ((!j || rng[j-1].ss <= y) && (j==m-1 || rng[j+1].ff >= y)) {
      B[j].pb(a[i]);
      pos[i] = j;
      build_block(j, true);
      break;
    }
  }
  return solve();
}

Compilation message (stderr)

elephants.cpp: In function 'void build_block(int, bool)':
elephants.cpp:39:28: error: 'INF' was not declared in this scope
   39 |     rng[id] = pii(id==0 ? -INF : rng[id-1].ss, id==m-1 ? INF, rng[id+1].ff);
      |                            ^~~
elephants.cpp:39:18: error: expected primary-expression before '(' token
   39 |     rng[id] = pii(id==0 ? -INF : rng[id-1].ss, id==m-1 ? INF, rng[id+1].ff);
      |                  ^
elephants.cpp:39:75: error: expected ':' before ')' token
   39 |     rng[id] = pii(id==0 ? -INF : rng[id-1].ss, id==m-1 ? INF, rng[id+1].ff);
      |                                                                           ^
elephants.cpp:39:75: error: expected primary-expression before ')' token