Submission #1007589

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007589		PenguinsAreCute	Counting Mushrooms (IOI20_mushrooms)	C++17	80.14 / 100	7 ms	596 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
int arr1[6]={8,1,12,3,14,7};
int arr2[7]={69,4,20-7,6,9,4-2+0*9,11};
int SQ = 140;
int count_mushrooms(int n) {
	if(n<=2*SQ) {
	 	int ans = 1;
	 		for(int i=1;i<n;i++) ans += !use_machine({0,i});
	 		return ans;
 	}
 	vector<int> A={0}, B;
	for(int i=1;i<=2*SQ;i+=2) {
		if(A.size()<2) {
			int erm = use_machine({i,0,i+1});
			if(!erm)
				A.push_back(i),
				A.push_back(i+1);
			else if(erm==2)
				B.push_back(i),
				B.push_back(i+1);
			else if(use_machine({0,i}))
				B.push_back(i),
				A.push_back(i+1);
			else
				A.push_back(i),
				B.push_back(i+1);
		} else {
			int guy = use_machine({i,A[0],i+1,A[1]});
			for(int j=0;j<2;j++) {
				if(guy&(1<<j)) B.push_back(i+j);
				else A.push_back(i+j);
			}
		}
	}
 	int ans = A.size();
 	if(A.size()>B.size()) {
 		vector<int> v={A[0]};
 		for(int j=2*SQ+1;j<n;j++) {
 			v.push_back(j);
 			v.push_back(A[((j-1)%SQ)+1]);
 			if(j==n-1||(!(j%SQ))) {ans += (v.size()-1-use_machine(v))/2; v={A[0]};}
 		}
 	} else {
 		vector<int> v={B[0]};
 		for(int j=2*SQ+1;j<n;j++) {
 			v.push_back(j);
 			v.push_back(B[((j-1)%SQ)+1]);
 			if(j==n-1||!(j%SQ)) {ans += use_machine(v)/2; v={B[0]};}
 		}
 	}
 	return ans;
}

• Subtask 1: 80.1418 / 100