Submission #433972

#	Time	Username	Problem	Language	Result	Execution time	Memory
433972		alishahali1382	Minerals (JOI19_minerals)	C++14	100 / 100	123 ms	4176 KiB

minerals

#include "minerals.h"
#include <bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef vector<int> vi;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) {cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;}
#define all(x) x.begin(), x.end()
#define pb push_back
#define SZ(x) ((int)x.size())

const int inf=1000000010;
const ll INF=1000000000000001000LL;
const int mod=1000000007;
const int MAXN=100010, LOG=20;

int n, m, k, u, v, x, y, a, b, t, ans;
int mark[MAXN];
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int Ask(int x){
	mark[x]^=1;
	return ans=Query(x);
}
int diff(vi &vec){
	int ted=0;
	for (int x:vec) ted+=mark[x];
	return abs(SZ(vec)/2 - ted);
}

void divide(vi X, vi Y){
	if (SZ(X)==1){
		Answer(X[0], Y[0]);
		return ;
	}
	if (diff(X)>diff(Y)) swap(X, Y);
	int sz=SZ(X), mid=sz/2;
	shuffle(all(Y), rng);
	sort(all(X), [](int i, int j){
		return mark[i]>mark[j];
	});
	vi X1, X2, Y1, Y2;
	for (int i=0; i<sz; i++){
		if (i<mid) X1.pb(X[i]);
		else X2.pb(X[i]);
	}
	for (int x:X1) if (!mark[x]) Ask(x);
	for (int x:X2) if (mark[x]) Ask(x);
	for (int y:Y){
		if (SZ(Y1)==mid) Y2.pb(y);
		else if (SZ(Y2)==sz-mid) Y1.pb(y);
		else{
			int last=ans;
			if (Ask(y)==last) Y1.pb(y);
			else Y2.pb(y);
		}
	}
	divide(X1, Y1);
	divide(X2, Y2);
}

void Solve(int _n){
	n=_n;
	vi X, Y, P(2*n);
	iota(all(P), 1);
	shuffle(all(P), rng);
	for (int i:P){
		int last=ans;
		if (SZ(X)==n || Ask(i)==last) Y.pb(i);
		else X.pb(i);
	}
	divide(X, Y);
}

• Subtask 1: 6 / 6
• Subtask 2: 25 / 25
• Subtask 3: 9 / 9
• Subtask 4: 30 / 30
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 10 / 10