Submission #415142

#	Time	Username	Problem	Language	Result	Execution time	Memory
415142		Bill_00	The Big Prize (IOI17_prize)	C++14	97.61 / 100	87 ms	1952 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int l[200005],r[200005],x[200005],answer=-1;
void solve(int L,int R){
	if(answer!=-1) return;
	if(L+1==R){
		return;
	}
	int m=(L+R)>>1;
	vector<int>res=ask(m);
	l[m]=res[0];
	r[m]=res[1];
	if(l[m]+r[m]==0){
		answer=m;
		return;
	}
	if(l[m]!=l[R] || r[m]!=r[R]){
		solve(m,R);
	}
	if(answer!=-1) return;
	if(l[m]!=l[L] || r[m]!=r[L]){
		solve(L,m);
	}
}
int find_best(int n){
	// for(int i = 0; i < n; i++){
	// 	std::vector<int> res = ask(i);
	// 	if(res[0] + res[1] == 0)
	// 		return i;
	// }
	for(int i=0;i<n;i++){
		l[i]=r[i]=-1;
	}
	int m=(n-1)/2;
	vector<int>res=ask(0);
	l[0]=res[0];
	r[0]=res[1];
	if(l[0]+r[0]==0) return 0;
	res=ask(n-1);
	l[n-1]=res[0];
	r[n-1]=res[1];
	if(l[n-1]+r[n-1]==0) return n-1;
	solve(0,n-1);
	return answer;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:35:6: warning: unused variable 'm' [-Wunused-variable]
   35 |  int m=(n-1)/2;
      |      ^

• Subtask 1: 20 / 20
• Subtask 2: 77.61 / 80