Submission #434790

#	Time	Username	Problem	Language	Result	Execution time	Memory
434790		dutch	커다란 상품 (IOI17_prize)	C++17	92.98 / 100	68 ms	328 KiB

prize

#include <bits/stdc++.h>
#include "prize.h"
using namespace std;
 
const int LIM = 480;
int ans, val;
 
void search(int l, int r, int lx, int rx){
	if(l > r || ans >= 0 || lx + rx == val) return;
	int m1 = (l + r) / 2, m2 = m1 + 1, x, y, cnt = 0;
	vector<int> q = {0, 0};
	while(cnt < val - lx - rx){
		if((y = m1-l > r-m2)) x = m1--;
		else x = m2++;
 
		q = ask(x);
		if(q[0] + q[1] == 0) return void(ans = x);
		if(q[0] + q[1] < val) ++cnt;
		else break;
	}
 
	q[!y] += cnt;
 
	search(l, m1, lx, q[1]);
	search(m2, r, q[0], rx);
}
 
int find_best(int n){
  	ans = val = -1;
  	map<int, int> c;
	for(int i=0; i<min(n, LIM); ++i){
		vector<int> q = ask(i);
		val = max(val, q[0] + q[1]);
		++c[q[0] + q[1]];
		if(q[0] + q[1] == 0) return i;
		val = max(val, q[0] + q[1]);
	}
	int cnt = 0;
	for(auto [i, j] : c) if(i < val) cnt += j;
 
	if(LIM < n) search(LIM, n-1, cnt, 0);
	return ans;
}

Compilation message (stderr)

prize.cpp: In function 'void search(int, int, int, int)':
prize.cpp:10:40: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   10 |  int m1 = (l + r) / 2, m2 = m1 + 1, x, y, cnt = 0;
      |                                        ^

• Subtask 1: 20 / 20
• Subtask 2: 72.98 / 80