Submission #1074330

#	Time	Username	Problem	Language	Result	Execution time	Memory
1074330		c2zi6	Rarest Insects (IOI22_insects)	C++17	47.50 / 100	172 ms	1264 KiB

insects

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "insects.h"

mt19937 rng;
VI rngind;
void movein(int i) {
    move_inside(rngind[i]);
}
void moveout(int i) {
    move_outside(rngind[i]);
}

int n, D;

int solution1() {
    VI vis(n);
    int ans = 2e9;
    replr(i, 0, n-1) if (!vis[i]) {
        vis[i] = true;
        movein(i);
        int cnt = 1;
        replr(j, i+1, n-1) if (!vis[j]) {
            movein(j);
            if (press_button() == 2) {
                vis[j] = true;
                cnt++;
            }
            moveout(j);
        }
        setmin(ans, cnt);
        moveout(i);
    }
    return ans;
}
int solution2() {
    VI vis(n);
    int k = -1;
    int ans = 0;
    replr(i, 0, n-1) if (!vis[i]) {
        vis[i] = true;
        movein(i);
        VI a;
        a.pb(i);
        replr(j, i+1, n-1) if (!vis[j]) {
            movein(j);
            if (press_button() == 2) {
                moveout(j);
            } else {
                vis[j] = true;
                a.pb(j);
            }
        }
        for (int i : a) moveout(i);
        if (k == -1) {
            k = a.size();
        } else if (a.size() != k) break;
        ans++;
    }
    return ans;
}

bool check(int k) {
    // is answer >= k
    VI a;
    rep(i, n) {
        movein(i);
        if (press_button() > k) moveout(i);
        else a.pb(i);
    }
    bool ret = (a.size() == D * k);
    for (int i : a) moveout(i);
    return ret;
}

int min_cardinality(int N) {
    rng = mt19937(chrono::steady_clock().now().time_since_epoch().count());
    n = N;
    rngind = VI(n);
    rep(i, n) rngind[i] = i;
    /*shuffle(all(rngind), rng);*/
    if (true) {
        movein(0);
        VI a;
        a.pb(0);
        replr(j, 1, n-1) {
            movein(j);
            if (press_button() == 2) moveout(j);
            else a.pb(j);
        }
        for (int i : a) moveout(i);
        D = a.size();
    }

    /*cout << D << endl;*/
    /*replr(k, 0, n-1) cout << check(k) << " ";*/
    /*cout << endl;*/
    
    int l = 1, r = n+1;
    while (l + 1 < r) {
        int m = (l + r) / 2;
        if (check(m)) l = m;
        else r = m;
    }
    return l;

    if (D < sqrt(n)) return solution1();
    return solution2();


    return -1;

}

Compilation message (stderr)

insects.cpp: In function 'int solution2()':
insects.cpp:86:29: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   86 |         } else if (a.size() != k) break;
      |                    ~~~~~~~~~^~~~
insects.cpp: In function 'bool check(int)':
insects.cpp:100:26: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  100 |     bool ret = (a.size() == D * k);
      |                 ~~~~~~~~~^~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 22.5 / 75