Submission #628126

#	Time	Username	Problem	Language	Result	Execution time	Memory
628126		Cross_Ratio	Rarest Insects (IOI22_insects)	C++17	99.95 / 100	69 ms	1364 KiB

insects

//#include "insects.h"
#include <bits/stdc++.h>
using namespace std;
map<int,set<int>> MS;
void move_inside(int);
void move_outside(int);
int press_button();
int min_cardinality(int N) {
    int i, j;
    set<int> S, S2;
    move_inside(0);
    S.insert(0);
    for(i=1;i<N;i++) {
        move_inside(i);
        S.insert(i);
        int c = press_button();
        if(c >= 2) {
            move_outside(i);
            S.erase(i);
        }
    }
    for(i=0;i<N;i++) S2.insert(i);
    int k = S.size();
    MS[1] = S;
    int s = 1, e = N/k+1;
    if(e==s+1) return s;
    int mid = (s+e)/2;
    int id = -1;
    int v = 1;
    for(int i : S2) {
        if(S.find(i)==S.end()) {
            move_inside(i);
            S.insert(i);
            int c = press_button();
            if(c>v) {
                v = c;
                id = i;
            }
            if(c >= mid+1) {
                move_outside(i);
                S.erase(i);
            }
            if(S.size()==k*mid) break;
        }
        if(S.size()==k*mid) break;
    }
    MS[mid] = S;
    while(s+1<e) {
        int mid = (s+e)/2;
        if(S.size()==k*mid) {
            s = mid;
            if(mid+1>=e) break;
            mid = (s+e)/2;
            for(int i : S2) {
                if(S.size()==k*mid) break;
                if(S.find(i)==S.end()) {
                    move_inside(i);
                    S.insert(i);
                    int c = press_button();
                    if(c>v) {
                        v = c;
                        id = i;
                    }
                    if(c >= mid+1) {
                        move_outside(i);
                        S.erase(i);
                    }
                    if(S.size()==k*mid) break;
                }
                if(S.size()==k*mid) break;
            }
            MS[mid] = S;
        }
        else {
            e = mid;
            if(s+1>=e) break;
            vector<int> era;
            for(int m : S2) {
                if(S.find(m)==S.end()) era.push_back(m);
            }
            for(int i : era) S2.erase(i);
            S2.erase(id);
            S.erase(id);
            mid = (s+e)/2;
            auto it = MS.upper_bound(mid);
            it--;
            set<int> S3 = it->second;
            for(i=0;i<N;i++) {
                if(S3.find(i)!=S3.end()&&S.find(i)==S.end()) {
                    move_inside(i);
                    S.insert(i);
                }
                if(S3.find(i)==S3.end()&&S.find(i)!=S.end()) {
                    move_outside(i);
                    S.erase(i);
                }
            }
            id = -1;
            v = -1;
            for(int i : S2) {
                if(S.find(i)==S.end()) {
                    move_inside(i);
                    S.insert(i);
                    int c = press_button();
                    if(c>v) {
                        v = c;
                        id = i;
                    }
                    if(c >= mid+1) {
                        move_outside(i);
                        S.erase(i);
                    }
                    if(S.size()==k*mid) break;
                }
                if(S.size()==k*mid) break;
            }
            MS[mid] = S;
        }
    }
    return s;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:43:24: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   43 |             if(S.size()==k*mid) break;
      |                ~~~~~~~~^~~~~~~
insects.cpp:45:20: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |         if(S.size()==k*mid) break;
      |            ~~~~~~~~^~~~~~~
insects.cpp:50:20: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   50 |         if(S.size()==k*mid) {
      |            ~~~~~~~~^~~~~~~
insects.cpp:55:28: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   55 |                 if(S.size()==k*mid) break;
      |                    ~~~~~~~~^~~~~~~
insects.cpp:68:32: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   68 |                     if(S.size()==k*mid) break;
      |                        ~~~~~~~~^~~~~~~
insects.cpp:70:28: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   70 |                 if(S.size()==k*mid) break;
      |                    ~~~~~~~~^~~~~~~
insects.cpp:113:32: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  113 |                     if(S.size()==k*mid) break;
      |                        ~~~~~~~~^~~~~~~
insects.cpp:115:28: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  115 |                 if(S.size()==k*mid) break;
      |                    ~~~~~~~~^~~~~~~
insects.cpp:9:12: warning: unused variable 'j' [-Wunused-variable]
    9 |     int i, j;
      |            ^

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 74.95 / 75