Submission #597306

#	Time	Username	Problem	Language	Result	Execution time	Memory
597306		Soumya1	The Big Prize (IOI17_prize)	C++17	99.68 / 100	55 ms	5320 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
const int S = 500;
vector<vector<int>> a;
int ans, mx;
vector<int> query(int i) {
	if (a[i].size()) return a[i];
	return a[i] = ask(i);
}
void solve(int l, int r, int pref, int suf) {
	if (l > r) return;
	if (pref + suf == mx) return; 
	int m = (l + r) >> 1;
	while (m >= l) {
		auto g = query(m);
		if (g[0] + g[1] == 0) {
			ans = m;
			return;
		}
		if (g[0] + g[1] == mx) {
			int tot = g[0] - pref;
			solve(l, m - 1, pref, g[1]);
			break;
		}
		m--;
	}
	if (m <= l) {
		solve((l + r) / 2 + 1, r, query((l + r) / 2 + 1)[0], suf);
	} else {
		solve(m + 1, r, query(m)[0], suf);
	}
}
int find_best(int n) {
	a.resize(n);
	if (n <= 5000) {
		for (int i = 0; i < n; i++) {
			auto g = query(i);
			if (g[0] + g[1] == 0) return i;
		}
	}
	int who = 0;
	for (int i = 0; i < S; i++) {
		auto g = query(i);
		if (mx < g[0] + g[1]) {
			mx = g[0] + g[1];
			who = i;
		}
		if (1LL * (g[0] + g[1]) * (g[0] + g[1]) > n) {
			who = i;
			break;
		}
		if (g[0] + g[1] == 0) {
			return i;
		}
	}
	int r = n - 1;
	while (r >= who) {
		auto g = query(r);
		if (g[0] + g[1] == 0) return r;
		if (g[0] + g[1] == mx) break;
		r--;
	}
	solve(who + 1, r - 1, query(who)[0], query(r)[1]);
	return ans;
}

Compilation message (stderr)

prize.cpp: In function 'void solve(int, int, int, int)':
prize.cpp:22:8: warning: unused variable 'tot' [-Wunused-variable]
   22 |    int tot = g[0] - pref;
      |        ^~~

• Subtask 1: 20 / 20
• Subtask 2: 79.68 / 80