Submission #69945

#	Time	Username	Problem	Language	Result	Execution time	Memory
69945		Diuven	The Big Prize (IOI17_prize)	C++14	98.84 / 100	85 ms	2240 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
typedef vector<int> vi;
const int MX=200010;
 
bool up[MX];
int L[MX], R[MX], sum, n, ans=-1;
 
void my_ask(int i){
	if(L[i]>=0) return;
	vi now=ask(i);
	L[i]=now[0], R[i]=now[1];
}
 
void search(int s, int e, int lc, int mc, int rc){
	if(s>e || mc<=0) return;
 
	int m=(s+e)/2;
 
	for(int i=m; i<=e; i++){
		my_ask(i);
		if(L[i]+R[i]==0){ ans=i; return; }
		if(L[i]+R[i]==sum){
			search(s,m-1, lc, L[i]-(i-m)-lc, R[i]+i-m);
			search(i+1,e, L[i], R[i]-rc, rc);
			return;
		}
	}
	for(int i=m; i>=s; i--){
		my_ask(i);
		if(L[i]+R[i]==0){ ans=i; return; }
		if(L[i]+R[i]==sum){
			search(s,i-1, lc, L[i]-lc, R[i]);
			return;
		}
	}
}
 
void solve(){
	int b=0;
	for(; b*b<=n; b++);
	vector<int> V;
    for(int ii=0; ii*b<n; ii++){
        int i=ii*b;
        my_ask(i); if(i+1<n) my_ask(i+1);
        sum=max({sum, L[i]+R[i], L[i+1]+R[i+1]});
    }
	V.push_back(0);
	for(int ii=0; ii*b<n; ii++){
		for(int j=ii*b; j<min(n, ii*b+b); j++){
			my_ask(j);
			if(L[j]+R[j]==sum){
				V.push_back(j);
				break;
			}
		}
	}
	V.push_back(n);
	for(int i=0; i<(int)V.size()-1; i++){
		int s=V[i], e=V[i+1];
		my_ask(s); if(e<n) my_ask(e);
		int l=L[s], r=0;
		if(e<n) r = R[e] + (L[e]+R[e]<sum);
		search(s,e-1,l,sum-l-r,r);
	}
}
 
int find_best(int _n){
	n=_n;
	for(int i=0; i<n; i++) L[i]=R[i]=-1;
	solve();
	assert(ans>=0 && L[ans]==0 && R[ans]==0);
	return ans;
}

• Subtask 1: 20 / 20
• Subtask 2: 78.84 / 80