Submission #1230497

#	Time	Username	Problem	Language	Result	Execution time	Memory
1230497		dssfsuper2	Counting Mushrooms (IOI20_mushrooms)	C++20	0 / 100	1 ms	436 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
vector<int> state;
int flip(int k){
	if (k==2) return 1;
	return 2;
}
pii check(int i, int j){
	if(state[0]==state[1] && state[1]==state[2]){
		int x = use_machine({0, i, 1, 2, j});
		if(state[0]==1)return {((x&2)>>1)+1, (x&1)+1};
		else return {flip(((x&2)>>1)+1), flip((x&1)+1)};
	}
	if(state[0]==state[1]){
		int x = use_machine({0, i, 1, 2, j})-1;
		if(state[0]==1)return {((x&2)>>1)+1, flip((x&1)+1)};
		else return {flip(((x&2)>>1)+1), (x&1)+1};
	}
	if(state[1]==state[2]){
		int x = use_machine({1, i, 2, 0, j})-1;
		//cout << x << '\n';
		//cout << 1 << ' ' << i << ' '<< 2 << ' ' << 0 << ' ' << j << '\n';
		if(state[1]==1)return {((x&2)>>1)+1, flip((x&1)+1)};
		else return {flip(((x&2)>>1)+1), (x&1)+1};
	}
	if(state[0]==state[2]){
		
		int x = use_machine({0, i, 2, 1, j})-1;
		if(state[0]==1)return {((x&2)>>1)+1, flip((x&1)+1)};
		else return {flip(((x&2)>>1)+1), (x&1)+1};
	}
}
int test(vector<int> tester, vector<int> tested, int tri){
	vector<int> cun;
	for(int i = 0;i<tester.size();i++){
		cun.push_back(tester[i]);
		cun.push_back(tested[i]);
	}
	auto x = use_machine(cun);
	int cn=x/2+(x&1);
	if(tri==2)cn=tester.size()-cn;
	return cn;
}
const int cut=200;
int count_mushrooms(int n) {
	
	state.assign(n, 0);
	//0 not known 1 A 2 B
	state[0]=1;
	int second = use_machine({0, 1})+1;
	state[1]=second;
	if(n==2)return 1+(second-1)^1;
	int third = use_machine({0, 2})+1;
	state[2]=third;
	if (n<=400){
		int res = 1+(second==1 ? 1:0) + (third==1 ? 1:0);
		//cout << "res: " << res << '\n';
		if (!(n&1))res+=use_machine({0, n-1})^1;
		for(int test=4;test<n;test+=2){
			auto x = check(test-1, test);
			//cout << x.first << ' ' << x.second << '\n';
			if(x.first==1)res++;
			if(x.second==1)res++;
		}
		return res;
	}
	else{
		for(int tes=4;tes<cut;tes+=2){
			auto x = check(tes-1, tes);
			state[tes-1]=x.first;
			state[tes]=x.second;
		}
	}
	vector<int> as, bs;
	int res = 0;
	for(int i =0;i<cut;i++){
		if (state[i]==1){
			as.push_back(i);
			res++;
		}
		else bs.push_back(i);
	}
	int ntt=1;
	if (as.size()<bs.size()){
		swap(as, bs);
		ntt=2;
	}
	vector<int> uki;
	for(int i = 0;i<n;i++){
		if(state[i]==0)uki.push_back(i);
	}
	while(uki.size()!=0){
		if (uki.size()>=as.size()){
			vector<int> tes;
			for(int i = 0;i<as.size();i++){
				tes.push_back(uki.back());
				uki.pop_back();
			}
			res+=test(as, tes, ntt);
		}
		else{
			while(uki.size()<as.size()){
				as.pop_back();
				res+=test(as, uki, ntt);
			}
			uki={};
		}
	}
	return res;
}

Compilation message (stderr)

mushrooms.cpp: In function 'pii check(int, int)':
mushrooms.cpp:34:1: warning: control reaches end of non-void function [-Wreturn-type]
   34 | }
      | ^

• Subtask 1: 0 / 100