Submission #410089

#	Time	Username	Problem	Language	Result	Execution time	Memory
410089		dreezy	The Big Prize (IOI17_prize)	C++17	20 / 100	120 ms	292 KiB

prize

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

/*********************************************************************************************************************/

int find_best(int n) {
	
	int curtotal = -1;
	for(int i =0; i<10; i++){
		vector<int> res= ask(n/10 *i);
		if( !res[0] && !res[1]) return n/10 *i;
		curtotal = max(curtotal,res[0] +res[1]);
	}

	
	int left = 0, right = n-1;
	int target =1;
	vector<bool> vis(n, 0);
	int cnt =0;
	while(true){
		int ind = (left +right) /2 ;
		//cout << left <<", "<<ind<<", "<<right<<": "<<target<<" "<<curtotal<<endl;

		vector<int> res = ask(ind);
		vis[ind] = true;
		
		if(res[0] + res[1] == 0)
			return ind;
		if(res[0] + res[1] < curtotal){
			int numvis = 1;
			res = ask(--ind);
			while(res[0]+ res[1] < curtotal){
				if(res[0] + res[1] == 0)
					return ind;
				vis[ind] = true;
				numvis++;
				--ind;
				
				//cout <<ind<<":"<<endl;
				if(ind <0){
					target = res[0]+numvis+1;
					break;
				}
				if(vis[ind])
				{
					target = res[0]+numvis+1;
					break;
				}
				
				res = ask(ind);
					
				
			}
			
			if(res[0] + res[1] == curtotal){
				target = max(res[0]+ numvis +1, target +1);
				left = ind +1;
				right = n-1;
			}
			
			
		}
		
		if(res[0] < target){
			left = ind +1;
		}
		else{
			right = ind - 1;
		}
		//cnt++;
		//if(cnt >=20) break;
	}
	
	return 0;
}


/*********************************************************************************************************************/

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:20:6: warning: unused variable 'cnt' [-Wunused-variable]
   20 |  int cnt =0;
      |      ^~~

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