Submission #520697

#	Time	Username	Problem	Language	Result	Execution time	Memory
520697		d4xn	The Big Prize (IOI17_prize)	C++17	20 / 100	75 ms	1368 KiB

prize

#include "prize.h"
#include <vector>
#include <map>
using namespace std;

map<int, vector<int>> dp;

int search(int l, int r) {
	if (l > r) return -1;
	if (l == r) {
		vector<int> ans;
		if (dp.find(l) != dp.end()) ans = dp[l];
		else {
			ans = ask(l);
			dp[l] = ans;
		}

		if (ans[0] == 0 && ans[1] == 0) return l;
		return -1;
	}
	
	int m = (l+r)/2;
	vector<int> ans;
	if (dp.find(m) != dp.end()) ans = dp[m];
	else {
		ans = ask(m);
		dp[m] = ans;
	}
	
	if (ans[0] == 0 && ans[1] == 0) return m;
	else if (ans[0] == 0) {
		return search(m+1, r);
	}
	else if (ans[1] == 0) {
		return search(l, m-1);
	}
	else {
		int ans1, ans2;
		ans1 = search(l, m-1);
		ans2 = search(m+1, r);
		return (ans1 == -1 ? ans2 : ans1);
	}

	return -1;
}

int find_best(int n) {
	return search(0, n-1);
}

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