Submission #1013417

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013417		NintsiChkhaidze	The Big Prize (IOI17_prize)	C++17	90 / 100	56 ms	6048 KiB

prize

#include <bits/stdc++.h>
#define pb push_back
#include "prize.h"
using namespace std;
 
bool fix[200003];
int Q;
vector <int> dp[200003];
 
vector <int> askk(int x){
	if (dp[x].size()) return dp[x];
	return dp[x] = ask(x);
}
 
int find_best(int n){
	
	int block = 500,mx = -1,idx = -1;
	vector <int> opt;
		
	for (int i = 0; i < min(n,block); i++){
		vector <int> vec = askk(i);
		int sum = vec[0] + vec[1];
		if (sum == 0) return i;
		
		if (sum > mx){
			mx = sum;
			opt = vec;
			idx = i;
		}
	}
 
	for (int i = idx; i < n; i++){
		vector <int> vec = askk(i);
		if (vec[0] + vec[1] == 0) {
			return i;
		}
		if (vec[0] + vec[1] != mx) {
			fix[i] = 1;
			continue;
		}
		
		opt = vec;
		int id = i;
		int l = i, r = n - 1,res = i;
		
		while (l <= r){
			int mid = (l + r)/2;
			vector <int> vec = askk(mid);
			if (vec[0] + vec[1] == 0) {
				return mid;
			}
			
			if (vec != opt){
				r = mid - 1;
			}else{
				res = mid;
				l = mid + 1;
			}
		}
	
		for (int j = id; j <= res; j++)	
			fix[j] = 1;
			
		i = res;
	}
	
	for (int i = 0; i < n; i++){
		if (!fix[i]){
			vector <int> vec = askk(i);
			
			if (vec[0] + vec[1] == 0) {
				return i; 
			}
		}
	}
	
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:18:15: warning: control reaches end of non-void function [-Wreturn-type]
   18 |  vector <int> opt;
      |               ^~~

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80