Submission #613886

#	Time	Username	Problem	Language	Result	Execution time	Memory
613886		thezomb1e	The Big Prize (IOI17_prize)	C++17	90 / 100	105 ms	11300 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define eb emplace_back
#define pb push_back
#define ft first
#define sd second
#define pi pair<int, int>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define dbg(...) dbg_out(__VA_ARGS__)

using ll = long long;
using ld = long double;
using namespace std;
using namespace __gnu_pbds;

//Constants
const ll INF = 5 * 1e18;
const int IINF = 2 * 1e9;
const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ld PI = 3.14159265359;

//Templates
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) {return os << '(' << p.first << ", " << p.second << ')';}
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) {os << '['; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << ']';}
void dbg_out() {cerr << endl;}
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << H << ' '; dbg_out(T...); }
template<typename T> void mins(T& x, T y) {x = min(x, y);}
template<typename T> void maxs(T& x, T y) {x = max(x, y);}
template<typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T> using omset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

int find_best(int n) {
	vector<vector<int>> mem(n + 5, {-1, -1});
	auto myask = [&](int i) {
		if (mem[i][0] == -1) {
			return mem[i] = ask(i);
		} else {
			return mem[i];
		}
	};
	int mx = 0, mx_i;
	for (int i = 0; i < min(n, 480); i++) {
		vector<int> res = myask(i);
		int cur = res[0] + res[1];
		maxs(mx, cur);
		if (cur == mx) {
			mx_i = i;
		}
		if (cur == 0) return i;
	}
	int i = mx_i;
	while (i < n) {
		vector<int> cur = myask(i);
		int lo = i, hi = n - 1;
		int to = n;
		while (lo <= hi) {
			int mi = (lo + hi) / 2;
			vector<int> res = myask(mi);
			if (res[0] + res[1] == 0) return mi;
			if (res[0] + res[1] < mx) {
				to = mi;
				hi = mi - 1;
			} else {
				if (res[0] == cur[0]) {
					lo = mi + 1;
				} else {
					hi = mi - 1;
				}
			}
		}
		while (to < n) {
			vector<int> res = myask(to);
			if (res[0] + res[1] == 0) return to;
			if (res[0] + res[1] == mx) break;
			to++;
		}
		i = to;
	}
	return 0;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:59:28: warning: 'mx_i' may be used uninitialized in this function [-Wmaybe-uninitialized]
   59 |   vector<int> cur = myask(i);
      |                            ^

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80