Submission #70063

#	Time	Username	Problem	Language	Result	Execution time	Memory
70063		E869120	The Big Prize (IOI17_prize)	C++14	20 / 100	96 ms	1780 KiB

prize

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

vector<int>vec;int N;

pair<int,int> asks(int p){
	vector<int>Z = ask(p);
	return make_pair(Z[0],Z[1]);
}

int find_best(int n) {
	srand((unsigned)time(NULL));
	N=n;
	vector<int>vec;for(int i=0;i<n;i++) vec.push_back(i);
	
	while(vec.size()>=2){
		int minx=0;
		if(vec.size()>=30){
			for(int i=0;i<5;i++){
				pair<int,int>A=asks(vec[rand()%vec.size()]);
				minx=max(minx,A.first+A.second);
			}
		}
		else{
			for(int i=0;i<vec.size();i++){
				pair<int,int>A=asks(vec[i]);
				minx=max(minx,A.first+A.second);
			}
		}
		
		int s = 0;for(int i=0;i<20;i++){if((1<<i)<=vec.size()) s=i+1;}
		int cnt=0,ret=0;vector<int>vec2;
		while(true){
			int c = 0;
			for(int i=s-1;i>=0;i--){
				int pos = vec[min(c + (1<<i), (int)vec.size() - 1)];
				if(pos <= ret) c += (1<<i);
				else{
					pair<int,int>Z = asks(pos);
					if(Z.first+Z.second==minx && Z.first<=cnt) c+=(1<<i);
				}
			}
			if(c==(1<<s)-1){
				break;
			}
			else{
				// results = vec[c + 1]
				if(c == 0){
					int pos = vec[0];
					pair<int, int> Z = asks(pos);
					if(Z.first + Z.second != minx) c = -1;
				}
				vec2.push_back(vec[c + 1]);
				ret = vec[c + 1];
			}
			cnt++;
		}
		vec=vec2;
	}
	return vec[0];
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:26:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0;i<vec.size();i++){
                ~^~~~~~~~~~~
prize.cpp:32:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   int s = 0;for(int i=0;i<20;i++){if((1<<i)<=vec.size()) s=i+1;}
                                      ~~~~~~^~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 0 / 80