Submission #726775

#	Time	Username	Problem	Language	Result	Execution time	Memory
726775		Nelt	Rarest Insects (IOI22_insects)	C++17	100 / 100	53 ms	352 KiB

insects

#include "insects.h"

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

/* DEFINES */
#define S second
#define F first
#define ll long long
#define ull unsigned long long
#define ld long double
#define npos ULLONG_MAX
#define INF LLONG_MAX
#define vv(a) vector<a>
#define pp(a, b) pair<a, b>
#define pq(a) priority_queue<a>
#define qq(a) queue<a>
#define ss(a) set<a>
#define mm(a, b) map<a, b>
#define ump(a, b) unordered_map<a, b>
#define sync                      \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define elif else if
#define endl "\n"
#define allc(a) begin(a), end(a)
#define all(a) a, a + sizeof(a) / sizeof(a[0])
#define pb push_back
#define logi(a) __lg(a)
#define sqrt(a) sqrtl(a)
#define mpr make_pair
#define ins insert
using namespace std;
using namespace __gnu_pbds;
using namespace __cxx11;
typedef char chr;
typedef basic_string<chr> str;
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int min_cardinality(int n)
{
    if (n == 1)
        return 1;
    vv(ll) eq, uni;
    for (ll i = 0; i < n; i++)
    {
        move_inside(i);
        if (press_button() == 2)
            eq.pb(i), move_outside(i);
        else
            uni.pb(i);
    }
    ll l = 2, cntdiff = n - eq.size(), r = n / cntdiff, cur = cntdiff, ans = 1;
    if (cntdiff == 1)
        return n;
    if (cntdiff > (n >> 1))
        return 1;
    bool us[n];
    memset(us, 0, sizeof(us));
    ll deactive[n];
    memset(deactive, 0, sizeof(deactive));
    vv(ll) erase, tmp;
    for (ll i = 0; i < min((ll)eq.size(), ((l + r) >> 1) - cntdiff); i++)
        move_inside(eq[i]), cur++, us[eq[i]] = 1, erase.pb(eq[i]);
    if (eq.size() < ((l + r) >> 1) - cntdiff)
        erase.clear();
    reverse(allc(eq));
    while (l <= r)
    {
        ll mid = (l + r) >> 1;
        for (ll i : eq)
        {
            if (cur >= mid * cntdiff)
            {
                l = mid + 1;
                break;
            }
            if (us[i])
                continue;
            us[i] = 1;
            if (deactive[i] > mid)
            {
                tmp.pb(i), deactive[i] = max(deactive[i], mid + 1);
                continue;
            }
            move_inside(i);
            if (press_button() > mid)
                move_outside(i), tmp.pb(i), deactive[i] = max(deactive[i], mid + 1);
            else
                cur++, erase.pb(i);
            if (cur >= mid * cntdiff)
            {
                l = mid + 1;
                break;
            }
        }
        if (cur >= mid * cntdiff)
        {
            l = mid + 1, ans = mid;
            if (l > r)
                break;
            for (ll j : tmp)
                us[j] = 0;
            erase.clear();
            for (ll j = 0; j < min((ll)tmp.size(), ((l + r) >> 1) - mid); j++)
                move_inside(tmp[j]), cur++, us[tmp[j]] = 1, erase.pb(tmp[j]);
            if (tmp.size() <= ((l + r) >> 1) - mid)
                erase.clear();
            tmp.clear();
        }
        else
        {
            r = mid - 1;
            if (l > r)
                break;
            if (erase.size() < mid - ((l + r) >> 1))
                erase.clear();
            while (erase.size() >= mid - ((l + r) >> 1))
                move_outside(erase.back()), us[erase.back()] = 0, cur--, erase.pop_back();
            tmp.clear();
        }
    }
    return ans;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:72:19: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   72 |     if (eq.size() < ((l + r) >> 1) - cntdiff)
      |         ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
insects.cpp:114:28: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  114 |             if (tmp.size() <= ((l + r) >> 1) - mid)
      |                 ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
insects.cpp:123:30: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  123 |             if (erase.size() < mid - ((l + r) >> 1))
      |                 ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
insects.cpp:125:33: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  125 |             while (erase.size() >= mid - ((l + r) >> 1))
      |                    ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 75 / 75