Submission #232826

#	Time	Username	Problem	Language	Result	Execution time	Memory
232826		cfalas	The Big Prize (IOI17_prize)	C++14	100 / 100	343 ms	472108 KiB

prize

#include<bits/stdc++.h>
using namespace std;
#include "prize.h"
#define MID ((l+r)/2)
typedef vector<int> vi;
typedef pair<int, int> ii;
#define F first
#define S second

ii mem[1000000];
bool used[1000000];
set<int> s[10000000];
ii q(int x){
	if(used[x]) return mem[x];
	used[x] = true;
	vi a = ask(x);
	mem[x] = ii(a[0],a[1]);
	return mem[x];
}

int N;
int mina=0;
int rec(int l=0, int r=N-1){
	if(l>r) return -1;
	ii a = q(MID);
	if(a.F+a.S==0) return MID;

	int tot = a.F+a.S;
	auto it = s[a.F+a.S].insert(MID).F;
	if(it==s[tot].begin() || mem[*prev(it)] != mem[MID]){
		int b = rec(l,MID-1);
		if(b!=-1) return b;
	}
	if(it==--s[tot].end() || mem[*next(it)] != mem[MID]){
		int b = rec(MID+1,r);
		if(b!=-1) return b;
	}
	return -1;
}

int find_best(int n) {
	N = n;
	int l=0, r=n-1;
	int m;
	int pos=0;
	return rec();
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:43:6: warning: unused variable 'l' [-Wunused-variable]
  int l=0, r=n-1;
      ^
prize.cpp:43:11: warning: unused variable 'r' [-Wunused-variable]
  int l=0, r=n-1;
           ^
prize.cpp:44:6: warning: unused variable 'm' [-Wunused-variable]
  int m;
      ^
prize.cpp:45:6: warning: unused variable 'pos' [-Wunused-variable]
  int pos=0;
      ^~~

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