Submission #873855

#	Time	Username	Problem	Language	Result	Execution time	Memory
873855		NeroZein	Candies (JOI18_candies)	C++17	0 / 100	1 ms	348 KiB

candies

#include "bits/stdc++.h"
using namespace std;

#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; ++i) {
    cin >> a[i]; 
  }
  vector<long long> ps[2];
  for (int rep = 0; rep < 2; ++rep) {
    ps[rep].resize(n); 
    for (int i = 0; i < n; ++i) {
      if (i % 2 != rep % 2) {
        ps[rep][i] = (i ? ps[rep][i - 1] : 0);
        continue; 
      }
      ps[rep][i] = a[i];
      if (i) ps[rep][i] += ps[rep][i - 1];
    }
  }
  vector<int> id(n);
  iota(id.begin(), id.end(), 0);
  sort(id.begin(), id.end(), [&](int i, int j) {
    return a[i] > a[j]; 
  });
  set<pair<int, int>> se; 
  auto get_val = [&](int l, int r) {
    long long ret = 0;
    if (l % 2 == r % 2) {
      int pr = l % 2; 
      return make_pair(ps[pr][r] - (l ? ps[pr][l - 1] : 0), (r - l + 2) / 2); 
    }
    ret = ps[1][r] - (l ? ps[1][l - 1] : 0);
    ret = max(ret, ps[0][r] - (l ? ps[0][l - 1] : 0)); 
    return make_pair(ret, (r - l + 1) / 2); 
  };
  int ones = 0; 
  long long res = 0;
  auto edit = [&](int i) {
    auto it = se.lower_bound(make_pair(i, -1)); 
    bool nx = false, pre = false; 
    if (it != se.end() && it->first == i + 1) {
      nx = true; 
    }
    if (it != se.begin() && prev(it)->second == i - 1) {
      pre = true; 
    }
    if (pre && nx) {
      int l = prev(it)->first;
      auto [x, y] = get_val(l, prev(it)->second);
      se.erase(prev(it)); 
      res -= x;
      ones -= y;
      int r = it->second;
      auto [xx, yy] = get_val(it->first, r);
      res -= xx;
      ones -= yy;
      se.erase(it); 
      se.emplace(l, r); 
      auto [xxx, yyy] = get_val(l, r);
      res += xxx;
      ones += yyy;
    } else if (pre) {
      int l = prev(it)->first; 
      auto [x, y] = get_val(l, prev(it)->second);
      res -= x;
      ones -= y;
      se.erase(prev(it)); 
      int r = i; 
      se.emplace(l, r); 
      auto [xxx, yyy] = get_val(l, r);
      res += xxx;
      ones += yyy;
    } else if (nx) {
      int l = i; 
      int r = it->second;
      auto [xx, yy] = get_val(it->first, r);
      res -= xx;
      ones -= yy;
      se.erase(it); 
      se.emplace(l, r);
      auto [xxx, yyy] = get_val(l, r);
      res += xxx;
      ones += yyy; 
    } else {
      se.insert({i, i}); 
      res += a[i]; 
      ones++; 
    }
  }; 
  int pq = 1; 
  vector<long long> ans((n + 1) / 2 + 1); 
  for (int i = 0; i < n; ++i) {
    int j = i;
    while (j < n && a[id[j]] == a[id[i]]) {
      edit(id[j]); 
      j++; 
    }
    while (pq <= ones) {
      ans[pq] = res;
      pq++; 
    }
  }
  for (int i = 1; i <= (n + 1) / 2; ++i) {
    cout << ans[i] << '\n'; 
  }
  return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 92