Submission #898906

#	Time	Username	Problem	Language	Result	Execution time	Memory
898906		abcvuitunggio	Counting Mushrooms (IOI20_mushrooms)	C++17	56.93 / 100	5 ms	696 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
const int k=100;
vector <int> a,b;
int t,res,sz;
int count_mushrooms(int n){
	if (n<=227){
        for (int i=1;i<n;i++)
            res+=1-use_machine({0,i});
        return res+1;
	}
	a.push_back(0);
	for (int i=1;i<=k*2;i++){
        if (max(a.size(),b.size())==k)
            break;
        int x=use_machine({0,i});
        if (x)
            b.push_back(i);
        else
            a.push_back(i);
	}
	sz=a.size();
	t=(a.size()!=k);
	if (a.size()!=k)
        swap(a,b);
	for (int i=a.size()+b.size();i<n;i+=k*2){
        if (i==n-1){
            res+=abs(t-use_machine({0,i}));
            continue;
        }
        vector <int> ve;
        if (n-i<k){
            for (int j=i;j<n;j++){
                ve.push_back(a[j-i]);
                ve.push_back(j);
            }
            ve.push_back(a[n-i]);
            res+=use_machine(ve)/2;
            break;
        }
        for (int j=i;j<min(i+k+1,n);j++){
            ve.push_back(j);
            if (j-i<k)
                ve.push_back(a[j-i]);
        }
        if (n-i-1<k)
            ve.pop_back();
        int x=use_machine(ve);
        if (i==n-2){
            res+=x;
            continue;
        }
        int l=ve[0],r=ve.back();
        ve.clear();
        ve.push_back(l);
        for (int j=min(i+k+1,n);j<min(i+k*2,n);j++){
            ve.push_back(a[j-i-k-1]);
            ve.push_back(j);
        }
        ve.push_back(a[min(i+k*2,n)-min(i+k+1,n)]);
        ve.push_back(r);
        res+=(x+use_machine(ve))/2;
	}
	return (t?res:n-a.size()-b.size()-res)+sz;
}

• Subtask 1: 56.927 / 100