Submission #432623

#	Time	Username	Problem	Language	Result	Execution time	Memory
432623		Andyvanh1	Counting Mushrooms (IOI20_mushrooms)	C++14	92.62 / 100	12 ms	460 KiB

mushrooms

#include <bits/stdc++.h>
#include "mushrooms.h"
 
 
using namespace std;
 
#define vt vector
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define rep(i,x) for(int (i) = 0; (i) < (x); (i)++)
 
typedef long long ll;
typedef long double ld;
typedef vt<int> vi;
typedef pair<int,int> pii;
 
int naive(int n){
  int ans = 1;
  for(int i = 1; i < n; i++){
    ans+=use_machine({0,i})^1;
}return ans;
}
 
int count_mushrooms(int n){
  if(n<=100)return naive(n);
    int h1;
    int h2;
    if(n==2){
        return 2-use_machine({0,1});
    }
    int val1 = use_machine({0,1});
    int val2 = use_machine({0,2});
    bool bol = true;
    if(val1==val2&&val1==1)h1 = 1, h2 = 2, bol = false;
    else {
        h1 = 0;
        if(!val1)h2=1;
        else h2 = 2;
    }
    int k = min(88,(int)sqrt(n));
    vi count1 = {0};
    vi count2;
    if(!val1)count1.pb(1);
    else count2.pb(1);
    if(!val2)count1.pb(2);
    else count2.pb(2);
    for(int i = 3; i < 2*k; i+=2){
        int a = use_machine({h1,i,h2,i+1});
        if(a==0){
            if(bol){
                count1.pb(i);
                count1.pb(i+1);
            }else{
                count2.pb(i);
                count2.pb(i+1);
            }
        }else if(a==1){
            if(bol){
                count1.pb(i);
                count2.pb(i+1);
            }else{
                count2.pb(i);
                count1.pb(i+1);
            }
        }else if(a==2){
            if(bol){
                count2.pb(i);
                count1.pb(i+1);
            }else{
                count1.pb(i);
                count2.pb(i+1);
            }
        }else{
            if(bol){
                count2.pb(i);
                count2.pb(i+1);
            }else{
                count1.pb(i);
                count1.pb(i+1);
            }
        }
    }
    int ans = count1.size();
    int delta = 0;
    for(int i = 2*k+1; i < n; i+=max(count1.size(),count2.size())-delta){
        int prr = max(count1.size(), count2.size());
        if(n-i<max(count1.size(),count2.size())){
            if(count2.size()>count1.size()){
                vi cur;
                for(int j = 0; j < n-i; j++){
                    cur.pb(j+i);
                    cur.pb(count2[j]);
                }
                int a = use_machine(cur);
                return ans + (a+1)/2;
 
            }else{
                vi cur;
                for(int j = 0; j < n-i; j++){
                    cur.pb(j+i);
                    cur.pb(count1[j]);
                }
                int a = use_machine(cur);
 
                return ans + n-i-(a+1)/2;
 
            }
        }else{
            if(count2.size()>count1.size()){
                vi cur;
                for(int j = 0; j < count2.size(); j++){
                    cur.pb(j+i);
                    cur.pb(count2[j]);
                }
                int a = use_machine(cur);
                ans+=(a+1)/2;
                if(a%2==0){
                    count2.pb(i);
                }else{
                    count1.pb(i);
                }
 
            }else{
                vi cur;
                for(int j = 0; j < count1.size(); j++){
                    cur.pb(j+i);
                    cur.pb(count1[j]);
                }
                int a = use_machine(cur);
                ans+=count1.size()-(a+1)/2;
                 if(a%2==0){
                    count1.pb(i);
                }else{
                    count2.pb(i);
                }
            }
        }
        delta = max(count1.size(),count2.size())-prr;
    }
    return ans;
 
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:87:15: warning: comparison of integer expressions of different signedness: 'int' and 'const long unsigned int' [-Wsign-compare]
   87 |         if(n-i<max(count1.size(),count2.size())){
      |            ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mushrooms.cpp:111:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |                 for(int j = 0; j < count2.size(); j++){
      |                                ~~^~~~~~~~~~~~~~~
mushrooms.cpp:125:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |                 for(int j = 0; j < count1.size(); j++){
      |                                ~~^~~~~~~~~~~~~~~

• Subtask 1: 92.623 / 100