Submission #790674

#	Time	Username	Problem	Language	Result	Execution time	Memory
790674		ymm	The Big Prize (IOI17_prize)	C++17	100 / 100	40 ms	1976 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
typedef long long ll;
typedef std::pair<int,int> pii;
using namespace std;

jmp_buf jb;
int ans;

const int N = 200'010;
pii table[N];
int n;

pii query(int i) {
	if (table[i] != pii{})
		return table[i];
	auto tmp = ask(i);
	if (tmp[0] + tmp[1] == 0) {
		ans = i;
		longjmp(jb, 1);
	}
	return (table[i] = {tmp[0], tmp[1]});
}

void solve(int l, int r, int cl, int cr, int tot)
{
	if (cl + cr == tot)
		return;
	int m = (l+r)/2;
	Loop (i,0,r-l) {
		int pos = i%2? m-i/2-1: m+i/2;
		auto [x, y] = query(pos);
		if (x + y > tot) {
			solve(0, n, 0, 0, x + y);
			assert(!"unreachable");
		}
		if (x + y < tot)
			continue;
		solve(l, pos, cl, y, tot);
		solve(pos+1, r, x, cr, tot);
		return;
	}
}

int find_best(int n) {
	::n = n;
	if (setjmp(jb))
		return ans;
	auto [x, y] = query(n/2);
	solve(0, n, 0, 0, x+y);
	assert(!"unreachable");
}

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