Submission #1230629

#	Time	Username	Problem	Language	Result	Execution time	Memory
1230629		clemmy14	Counting Mushrooms (IOI20_mushrooms)	C++20	0 / 100	6 ms	584 KiB

mushrooms

#include<bits/stdc++.h>
#include "mushrooms.h"
using namespace std;

int firstTrue(int lo, int hi) {
	hi++;
	while(lo < hi) {
		int mid = lo+(hi-lo)/2;
		if(lo == mid) return lo+1;
		vector<int> cur;
		for(int i=lo; i<=mid; i++) cur.push_back(i);
		int nbAdj=use_machine(cur);
		if(nbAdj >= 1) hi=mid;
		else if(nbAdj == hi-lo) return lo+1;
		else lo=mid;
	}
	return lo+1;
}


int count_mushrooms(int n) {
	vector<int> a, b;
	int lo=0;
	bool aa=true;
	while(lo != n) {
		int lolo=firstTrue(lo, n-1);
		if(aa) for(int i=lo; i<lolo; i++) a.push_back(i);
		else for(int i=lo; i<lolo; i++) b.push_back(i);
		lo=lolo;
		aa=!aa;
		if(a.size() > sqrt(n) || b.size() > sqrt(n)) break;
	}
	int ans=0;
	if(a.size() > sqrt(n)) {
		set<int> s;
		for(auto x : a) s.insert(x);
		ans=a.size();

		for(int i=lo; i<n; i++) {
			vector<int> cur={a[0]};
			int idx=1;
			while(idx < a.size() && i < n) {
				if(s.count(i)) {
					i++; continue;
				}
				cur.push_back(i);
				cur.push_back(a[idx]);
				idx++; i++;
			}
			if(cur.size() == 1) continue;
			ans+=(cur.size()-use_machine(cur))/2;
			i--;
		}
	} else {
		set<int> s;
		for(auto x : b) s.insert(x);
		ans=b.size();
	
		for(int i=lo; i<n; i++) {
			vector<int> cur={b[0]};
			int idx=1;
			while(idx < b.size() && i < n) {
				if(s.count(i)) {
					i++; continue;
				}
				cur.push_back(i);
				cur.push_back(b[idx]);
				idx++; i++;
			}
			if(cur.size() == 1) continue;
			ans+=(cur.size()-use_machine(cur))/2;
			i--;
		}
		ans=n-ans;
	}
	return ans;
}

• Subtask 1: 0 / 100