제출 #731869

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
731869		sentheta	커다란 상품 (IOI17_prize)	C++17	100 / 100	54 ms	5256 KiB

prize

#include "prize.h"
// author : sentheta aka vanwij
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<cassert>
#include<random>
#include<chrono>
#include<cmath>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<stack>
#include<map>
#include<set>
using namespace std;

#define Int long long
#define V vector
#define pii pair<int,int>
#define ff first
#define ss second

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

#define pow2(x) (1LL<<(x))
#define msb(x) (63-__builtin_clzll(x))
#define bitcnt(x) (__builtin_popcountll(x))

#define nl '\n'
#define _ << ' ' <<
#define all(x) (x).begin(), (x).end()
#define rep(i,a,b) for(int i = (int)(a); i < (int)(b); i++)
#define dbg(x) if(1) cout << "?" << #x << " : " << (x) << endl << flush;


const int N = 2e5+5;
V<int> memo[N];
pii query(int i){
	if(memo[i].empty()) memo[i] = ask(i);
	return {memo[i][0], memo[i][1]};
}

int n;

#define mid (tl+tr)/2
#define lc (v+1)
#define rc (v+2*(mid-tl+1))
struct Segtree{
	int cnt[2*N];
	void upd(int i,int v=0,int tl=0,int tr=n-1){
		if(tl==tr){
			cnt[v] = 1; return;
		}
		if(i<=mid) upd(i, lc,tl,mid);
		else upd(i, rc,mid+1,tr);
		cnt[v] = cnt[lc] + cnt[rc];
	}
	int qry(int l,int r,int v=0,int tl=0,int tr=n-1){
		if(r<tl || tr<l) return 0;
		if(l<=tl && tr<=r) return cnt[v];
		return qry(l,r, lc,tl,mid) + qry(l,r, rc,mid+1,tr);
	}
} segtree;
#undef mid



int mx = 0;
int dnc(int lout=0,int rout=0,int l=0,int r=n-1){
	if(l > r) return -1;
	if(lout+rout+segtree.qry(l,r) == mx){
		// assert(0);
		return -1;
	}

	int midcnt = 0;
	for(int m=(l+r)/2; m<=r; m++){
		auto[lcnt,rcnt] = query(m);
		if(lcnt+rcnt==0) return m;
		if(lcnt+rcnt < mx){
			midcnt++; continue;
		}

		if(lcnt > lout+midcnt){
			int i = dnc(lout,midcnt+rcnt, l,(l+r)/2-1);
			if(i!=-1) return i;
		}
		if(rcnt > rout){
			int i = dnc(lcnt,rout, m+1,r);
			if(i!=-1) return i;
		}
		return -1;
	}

	for(int m=(l+r)/2-1; m>=l; m--){
		auto[lcnt,rcnt] = query(m);
		if(lcnt+rcnt==0) return m;
		if(lcnt+rcnt < mx){
			midcnt++; continue;
		}
		// assert(rcnt == midcnt + rout);

		if(lcnt > lout){
			int i = dnc(lout,rcnt, l,m-1);
			if(i!=-1) return i;
		}
		return -1;
	}

	return -1;
}


int find_best(int _n){
	n = _n;

	V<int> ord;
	for(int i=0; i<min(n,237); i++){
		ord.push_back(i);
	}
	for(int i=n-1; i>=max(n-237,0); i--){
		ord.push_back(i);
	}
	rep(i,0,ord.size()){
		swap(ord[i], ord[rng()%(i+1)]);
	}


	map<int,V<int>> mp;
	for(int j=0; j<ord.size(); j++){
		int i = ord[j];
	// for(int i=max(0,n/2-240); i<=min(n-1,n/2+240); i++){
	// rep(i,0,474){
		auto[lcnt,rcnt] = query(i);
		if(lcnt+rcnt==0) return i;

		mp[lcnt+rcnt].push_back(i);
		mx = max(mx, lcnt+rcnt);
		if(mp.size()==4) break;
		if(lcnt+rcnt>300) break;
	}
	assert((int)mp.size()<=4);

	for(auto&[x,v] : mp){
		if(x==mx){

		}
		else{
			for(int i : v){
				segtree.upd(i);
			}
		}
	}

	int ans = dnc();
	return ans;
}

컴파일 시 표준 에러 (stderr) 메시지

prize.cpp: In function 'int find_best(int)':
prize.cpp:132:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  132 |  for(int j=0; j<ord.size(); j++){
      |               ~^~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 80 / 80