Submission #363325

#	Time	Username	Problem	Language	Result	Execution time	Memory
363325		ryansee	Counting Mushrooms (IOI20_mushrooms)	C++14	100 / 100	10 ms	752 KiB

mushrooms

#include "mushrooms.h"
 
#include "bits/stdc++.h"
using namespace std;
 
#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusive
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }
 
using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(int i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 
 
long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (200006)
int B = 1, T = 100;
vector<int> join(int x, deque<int> dq) {
	vector<int> v;
	if(~x) v.eb(x);
	for(auto i:dq) v.eb(i);
	return v;
}
int count_mushrooms(int n) {
	deque<int> dq, co[2];
	FOR(i,1,n-1) dq.eb(i);
	co[0].eb(0);
	
	while(dq.size() && (max(co[0].size(), co[1].size()) < 3 || min(co[0].size(), co[1].size()) < 2) && max(co[0].size(), co[1].size()) < T) {
		if(max(co[0].size(), co[1].size()) < 2 || dq.size() == 1) {
			int res = use_machine({0, dq.front()});
			co[res].eb(dq.front()), dq.pop_front();
		} else {
			int x = dq.front(); dq.pop_front();
			int y = dq.front(); dq.pop_front();
			vector<int> v;
			if(co[0].size()>1) v.eb(co[0][0]);
			else v.eb(co[1][0]);
			v.eb(x);
			if(co[0].size()>1) v.eb(co[0][1]);
			else v.eb(co[1][1]);
			v.eb(y);
			int res = use_machine(v);
			auto declare=[&](int x,bool b){
				co[b].eb(x);
			};
			if(co[0].size()>1) {
				if(res & 1) declare(y, 1);
				else declare(y, 0);
				if(res > 1) declare(x, 1);
				else declare(x, 0);
			} else {
				if(res & 1) declare(y, 0);
				else declare(y, 1);
				if(res > 1) declare(x, 0);
				else declare(x, 1);
			}
		}
	} // change the above
	while(max(co[0].size(), co[1].size()) < T) {
		if(siz(dq) < 5) break;
		bool b = co[1].size() > co[0].size();
		if(b) co[0].swap(co[1]);
		if(co[0].size() < 3 || co[1].size() < 2) return 0;
		int x=dq.front(); dq.pop_front();
		int y=dq.front(); dq.pop_front();
		int z=dq.front(); dq.pop_front();
		vector<int> v = {co[0][0], x, co[0][1], y, co[0][2], z};
		int res = use_machine(v);
		if(res&1) co[1].eb(z), res ^= 1;
		else co[0].eb(z);
		if(res == 0) {
			co[0].eb(x), co[0].eb(y);
		} else if(res == 4) {
			co[1].eb(x), co[1].eb(y);
		} else if(res == 2) {
			// one of (x, y) is B, one A
			int w = dq.front(); dq.pop_front();
			int t = dq.front(); dq.pop_front();
			v = {w, co[0][0], t, co[0][1], x, co[0][2], co[1][0], y, co[1][1]};
			res = use_machine(v);
			-- res;
			if(res & 1) co[1].eb(w), res ^= 1;
			else co[0].eb(w);
			if(res == 0) {
				co[0].eb(t), co[0].eb(x), co[1].eb(y);
			} else if(res == 2) {
				co[1].eb(t), co[0].eb(x), co[1].eb(y);
			} else if(res == 4) {
				co[0].eb(t), co[1].eb(x), co[0].eb(y);
			} else if(res == 6) {
				co[1].eb(t), co[1].eb(x), co[0].eb(y);
			} else assert(0);
		} else assert(0);
		if(b) co[1].swap(co[0]);
	}
	
	int ans = co[0].size();
	int b = 0;
	if(co[b].size() < B) b = 1;
	for(int i=0;i<siz(dq);i+=B) {
		B = max(co[0].size(), co[1].size());
		if(siz(co[b]) ^ B) b ^= 1;
		vector<int> tmp;
		FOR(j,i,min((int)siz(dq)-1, i+B-1)) {
			tmp.eb(co[b][j-i]);
			tmp.eb(dq[j]);
		}
		int res = use_machine(tmp), cnt = 0;
		if(res & 1) ++ cnt, -- res, co[!b].eb(dq[min((int)siz(dq)-1, i+B-1)]);
		else co[b].eb(dq[min((int)siz(dq)-1, i+B-1)]);
		res /= 2;
		cnt += res;
		if(b==0) ans += min((int)siz(dq)-1, i+B-1) - i + 1 - cnt;
		else ans += cnt;
	}
	return ans;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:43:133: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   43 |  while(dq.size() && (max(co[0].size(), co[1].size()) < 3 || min(co[0].size(), co[1].size()) < 2) && max(co[0].size(), co[1].size()) < T) {
      |                                                                                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
mushrooms.cpp:74:40: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   74 |  while(max(co[0].size(), co[1].size()) < T) {
      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
mushrooms.cpp:114:18: warning: comparison of integer expressions of different signedness: 'std::deque<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  114 |  if(co[b].size() < B) b = 1;
      |     ~~~~~~~~~~~~~^~~

• Subtask 1: 100 / 100