Submission #152303

#	Time	Username	Problem	Language	Result	Execution time	Memory
152303		mieszko11b	The Big Prize (IOI17_prize)	C++14	100 / 100	65 ms	5240 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>

using namespace std;

#define X first
#define Y second

using ii = pair<int, int>;

int n;
vector<int> V[200007];

int worst_sum;

ii ans(int i) {
	if(V[i].size() == 0) {
		V[i] = ask(i);
		worst_sum = max(worst_sum, V[i][0] + V[i][1]);
	}
	return {V[i][0], V[i][1]};
}

int sum(int i) {
	return ans(i).X + ans(i).Y;
}

int find_in_segment(int a, int b, int ok) {
	if(!ok)
		return -1;
	
	int mid1 = (a + b) / 2;
	int mid2 = (a + b) / 2;
	
	for(int i = 0 ; i < 5 ; i++) {
		while(sum(a - 1) < worst_sum && a <= mid1) {
			if(sum(a) == 0)
				return a;
			a++;
		}
		while(sum(b + 1) < worst_sum && mid1 <= b) {
			if(sum(b) == 0)
				return b;
			b--;
		}
		
		while(sum(mid1) < worst_sum && mid1 >= a) {
			if(sum(mid1) == 0)
				return mid1;
			mid1--;
		}
		
		while(sum(mid2) < worst_sum && mid2 <= b) {
			if(sum(mid2) == 0)
				return mid2;
			mid2++;
		}
	}
	
	if(mid1 > a) {
		int x = find_in_segment(a, mid1 - 1, ans(mid1).X - ans(a - 1).X);
		if(x != -1)
			return x;
	}
	
	if(mid2 < b) {
		int x = find_in_segment(mid2 + 1, b, ans(b + 1).X - ans(mid2).X);
		if(x != -1)
			return x;
	}
	
	return -1;
}

int find_best(int n) {
	::n = n;
	
	int total = ans(0).Y;
	worst_sum = total;
	V[n] = {total, 0};
	if(total == 0) 
		return 0;
		
	return find_in_segment(1, n - 1, total);
}

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