Submission #643390

#	Time	Username	Problem	Language	Result	Execution time	Memory
643390		jamezzz	Counting Mushrooms (IOI20_mushrooms)	C++17	100 / 100	9 ms	468 KiB

mushrooms

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

#define pb push_back

int M=103;

int pop(vector<int> &v){
	int x=v.back();
	v.pop_back();
	return x;
}

int count_mushrooms(int n){
	vector<int> v[2],u;
	v[0]={0};
	for(int i=n-1;i>0;--i)u.pb(i);
	
	if(n<=227){
		while(!u.empty()){
			int x=pop(u);
			if(use_machine({0,x})==1)v[1].pb(x);
			else v[0].pb(x);
		}
		return v[0].size();
	}
	
	//phase 1
	for(int i=0;i<2;++i){
		int x=pop(u);
		if(use_machine({0,x})==1)v[1].pb(x);
		else v[0].pb(x);
	}
	int i=0;
	if(v[0].size()<2)i=1;
	int x=pop(u),y=pop(u);
	int res=use_machine({v[i][0],x,v[i][1],y});
	if(res==0)v[i].pb(x),v[i].pb(y);
	else if(res==1)v[i].pb(x),v[1-i].pb(y);
	else if(res==2)v[1-i].pb(x),v[i].pb(y);
	else v[1-i].pb(x),v[1-i].pb(y);
	
	/*
	printf("a: ");
	for(int x:v[0])printf("%d ",x);
	printf("\n");
	printf("b: ");
	for(int x:v[1])printf("%d ",x);
	printf("\n");
	*/
	
	//phase 2
	bool bad=false;
	while(v[0].size()+v[1].size()<2*M-1){
		int x=pop(u),y=pop(u),z=pop(u);
		if(bad){//y and z are different
			int i=0;
			if(v[0].size()<3)i=1;
			int res=use_machine({v[i][0],x,v[i][1],y,v[i][2],z});
			if(res==0)v[i].pb(x),v[i].pb(y),v[i].pb(z);
			else if(res==1)v[i].pb(x),v[i].pb(y),v[1-i].pb(z);
			else if(res==2)v[i].pb(x),v[1-i].pb(y),v[i].pb(z);
			else if(res==3)v[1-i].pb(x),v[i].pb(y),v[1-i].pb(z);
			else if(res==4)v[1-i].pb(x),v[1-i].pb(y),v[i].pb(z);
			else v[1-i].pb(x),v[1-i].pb(y),v[1-i].pb(z);
			bad=false;
		}
		else{
			int i=0;
			if(v[0].size()<3)i=1;
			int res=use_machine({v[i][0],x,v[i][1],y,v[i][2],z});
			if(res==0)v[i].pb(x),v[i].pb(y),v[i].pb(z);
			else if(res==1)v[i].pb(x),v[i].pb(y),v[1-i].pb(z);
			else if(res==2)bad=true,v[i].pb(z);
			else if(res==3)bad=true,v[1-i].pb(z);
			else if(res==4)v[1-i].pb(x),v[1-i].pb(y),v[i].pb(z);
			else v[1-i].pb(x),v[1-i].pb(y),v[1-i].pb(z);
		}
		/*
		printf("%d %d %d\n",x,y,z);
		printf("bad: %d\n",bad);
		printf("a: ");
		for(int x:v[0])printf("%d ",x);
		printf("\n");
		printf("b: ");
		for(int x:v[1])printf("%d ",x);
		printf("\n");
		*/
		if(!bad)continue;
		if(min(v[0].size(),v[1].size())<2){
			z=pop(u);
			u.pb(x),u.pb(y),u.pb(z);
		}
		else{
			int z=pop(u),w=pop(u);
			int i=0;
			if(v[0].size()<3)i=1;
			int res=use_machine({v[1-i][0],x,v[1-i][1],v[i][0],y,v[i][1],z,v[i][2],w});
			if(res==1)v[1-i].pb(x),v[i].pb(y),v[i].pb(z),v[i].pb(w);
			else if(res==2)v[1-i].pb(x),v[i].pb(y),v[i].pb(z),v[1-i].pb(w);
			else if(res==3)v[1-i].pb(x),v[i].pb(y),v[1-i].pb(z),v[i].pb(w);
			else if(res==4)v[1-i].pb(x),v[i].pb(y),v[1-i].pb(z),v[1-i].pb(w);
			else if(res==5)v[i].pb(x),v[1-i].pb(y),v[i].pb(z),v[i].pb(w);
			else if(res==6)v[i].pb(x),v[1-i].pb(y),v[i].pb(z),v[1-i].pb(w);
			else if(res==7)v[i].pb(x),v[1-i].pb(y),v[1-i].pb(z),v[i].pb(w);
			else v[i].pb(x),v[1-i].pb(y),v[1-i].pb(z),v[1-i].pb(w);
			bad=false;
		}
	}
	
	//phase 3
	int extra[2]={0,0};
	while(!u.empty()){
		int i=0;
		if(v[0].size()<v[1].size())i=1;
		int t=min(v[i].size(),u.size());
		vector<int> m;
		for(int x=0;x<t;++x){
			m.pb(v[i][x]);m.pb(pop(u));
		}
		int res=use_machine(m);
		if(res%2==1)v[1-i].pb(m.back());
		else v[i].pb(m.back());
		extra[i]+=(t-1)-res/2,extra[1-i]+=res/2;
	}
	
	return v[0].size()+extra[0];
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:55:31: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   55 |  while(v[0].size()+v[1].size()<2*M-1){
      |        ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~

• Subtask 1: 100 / 100