Submission #1021617

#	Time	Username	Problem	Language	Result	Execution time	Memory
1021617		Ahmed_Solyman	Counting Mushrooms (IOI20_mushrooms)	C++14	80.43 / 100	7 ms	604 KiB

mushrooms

/*
In the name of Allah
made by: Ahmed_Solyman
*/
#include <bits/stdc++.h>
 
using namespace std;
typedef long long ll;
 
int use_machine(vector<int>x);
int count_mushrooms(int n){
    if(n<=226){
        int ret=1;
        for(int i=1;i<n;i++){
            ret+=1-use_machine({0,i});
        }
        return ret;
    }
    int ret=0,k=137;
    vector<int>v[2];
    v[0].push_back(0);
    for(int i=1;i<=2;i++){
        if(use_machine({0,i})==0)v[0].push_back(i);
        else v[1].push_back(i);
    }
    bool typ;
    int x,y;
    if(v[0].size()>=2){
        typ=0;
        x=v[0][0];y=v[0][1];
    }
    else{
        typ=1;
        x=v[1][0];y=v[1][1];
    }
    for(int i=3;i<=2*k-2;i+=2){
        int h=use_machine({i,x,i+1,y});
        if(h==0){
            v[typ].push_back(i);
            v[typ].push_back(i+1);
        }
        if(h==1){
            v[typ^1].push_back(i);
            v[typ].push_back(i+1);
        }
        if(h==2){
            v[typ].push_back(i);
            v[typ^1].push_back(i+1);
        }
        if(h==3){
            v[typ^1].push_back(i);
            v[typ^1].push_back(i+1);
        }
    }
    vector<int>g;
    if(v[0].size()>v[1].size()){
        typ=0;
        g=v[0];
    }
    else{
        typ=1;        g=v[1];
    }
    auto f=[&](int l,int r){
        vector<int>p;
        for(int i=l;i<=r;i++){
            p.push_back(i);
            p.push_back(g[i-l]);
        }
        int g=use_machine(p);
        g=(g+1)/2;
        if(typ)return g;
        else return r-l+1-g;
    };
    ret=(int)v[0].size();
  	int mx=(int)v[typ].size();
    for(int i=2*k-1;i<n;i+=mx){
        ret+=f(i,min(i+mx-1,n-1));
    }
    return ret;
}

• Subtask 1: 80.427 / 100