Submission #352272

#	Time	Username	Problem	Language	Result	Execution time	Memory
352272		juggernaut	Counting Mushrooms (IOI20_mushrooms)	C++14	92.62 / 100	14 ms	640 KiB

mushrooms

#include"mushrooms.h"
#include<bits/stdc++.h>
//#include"stub.cpp"
using namespace std;
int count_mushrooms(int n){
    vector<int>a,b,id;
    int i=1,res=1,j;
    for(;i<n;i++)id.push_back(i);
    srand(time(NULL));
    random_shuffle(id.begin(),id.end());
    random_shuffle(id.begin(),id.end());
    random_shuffle(id.begin(),id.end());
    random_shuffle(id.begin(),id.end());
    random_shuffle(id.begin(),id.end());
    i=1;
    a.push_back(0);
    while(i<min(n,3)){
      	if(a.size()==2||b.size()==2)break;
        if(use_machine({0,id[i-1]}))b.push_back(id[i-1]);
        else a.push_back(id[i-1]),res++;
        i++;
    }
    while(i+1<min(170,n)){
        if(a.size()>b.size()){
            j=use_machine({a[0],id[i-1],a[1],id[i]});
            if(j&1)b.push_back(id[i]);
            else a.push_back(id[i]),res++;
            if(j&2)b.push_back(id[i-1]);
            else a.push_back(id[i-1]),res++;
        }else{
            j=use_machine({b[0],id[i-1],b[1],id[i]});
            if(j&1)a.push_back(id[i]),res++;
            else b.push_back(id[i]);
            if(j&2)a.push_back(id[i-1]),res++;
            else b.push_back(id[i-1]);
        }
        i+=2;
    }
    while(i<n){
        if(a.size()>b.size()){
            vector<int>v;
            for(j=0;j<a.size()&&i+j<n;j++){
                v.push_back(a[j]);
                v.push_back(id[i+j-1]);
            }
            i+=j;
            j=use_machine(v);
            if(j&1)b.push_back(v.back());
            else a.push_back(v.back());
            j++;
            j>>=1;
            res+=(((int(v.size()))>>1))-j;
        }else{
            vector<int>v;
            for(j=0;j<b.size()&&i+j<n;j++){
                v.push_back(b[j]);
                v.push_back(id[i+j-1]);
            }
            i+=j;
            j=use_machine(v);
            if(j&1)a.push_back(v.back());
            else b.push_back(v.back());
            j++;
            j>>=1;
            res+=j;
        }
    }
    return res;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:42:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |             for(j=0;j<a.size()&&i+j<n;j++){
      |                     ~^~~~~~~~~
mushrooms.cpp:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |             for(j=0;j<b.size()&&i+j<n;j++){
      |                     ~^~~~~~~~~

• Subtask 1: 92.623 / 100