Submission #830551

#	Time	Username	Problem	Language	Result	Execution time	Memory
830551		tolbi	Rarest Insects (IOI22_insects)	C++17	50 / 100	146 ms	312 KiB

insects

#include <bits/stdc++.h>
using namespace std;
mt19937 ayahya(chrono::high_resolution_clock().now().time_since_epoch().count());
#include "insects.h"
int min_cardinality(int n) {
    function<int(int)> f;
    vector<int> hash(n);
    iota(hash.begin(), hash.end(), 0);
    for (int i = n-1; i >= 0; i--){
        swap(hash[i],hash[ayahya()%(i+1)]);
    }
    map<int,int> cev;
    f = [&](int x)->int{
        if (cev.count(x)) return cev[x];
        int ans = 0;
        vector<int> crr;
        for (int i = 0; i < n; i++){
            crr.push_back(hash[i]);
            move_inside(hash[i]);
            if (press_button()>x){
                ans++;
                crr.pop_back();
                move_outside(hash[i]);
            }
        }
        for (int i = 0; i < crr.size(); ++i)
        {
            move_outside(crr[i]);
        }
        return cev[x]=ans;
    };
    int diff = n-f(1);
    if (diff==1) return n;
    int l = 1, r = n/diff;
    while (l<r){
        int mid = l+(r-l+1)/2;
        if (f(mid)>n-(mid*diff)){
            r=mid-1;
        }
        else l = mid;
    }
    return l;
}

Compilation message (stderr)

insects.cpp: In lambda function:
insects.cpp:26:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |         for (int i = 0; i < crr.size(); ++i)
      |                         ~~^~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 25 / 75