Submission #348697

#	Time	Username	Problem	Language	Result	Execution time	Memory
348697		ryansee	The Big Prize (IOI17_prize)	C++14	90 / 100	132 ms	2060 KiB

prize

#include "prize.h"

#include "bits/stdc++.h"
using namespace std;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 

long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (200006)

int memo[MAXN][2];

vector<int> my_ask(int x) {
	if(~memo[x][0]) return vector<int>() = {memo[x][0], memo[x][1]};
	vector<int> res = ask(x);
	memo[x][0] = res[0], memo[x][1] = res[1];
	return vector<int>() = {memo[x][0], memo[x][1]};
}

int find_best(int n) {
	mmst(memo, -1);
	vector<int> ans;
	vector<int> v(2, 0);
	ll x = -1;
	DEC(i,n-1,max(0, n-500)) {
		vector<int> res = my_ask(i);
		if(res[0] + res[1] > v[0] + v[1]) v = res, x = i;
	}
	assert(v[1] == (n-1) - x);
	FOR(i,x+1,n-1) ans.eb(i);
	
	ll bad = v[0] + v[1];
	
	while(v[0]) {
		ll st = 0, en = x;
		while(en-st>1) {
			ll mid=(st+en)>>1;
			vector<int> res = my_ask(mid);
			if(res[0] + res[1] != bad) {
				st = mid;
				continue;
			}
			if(res[0] == v[0]) en = mid;
			else st = mid;
		}
		
		back:;
		
		ans.eb(st);
		-- st;
		if(st < 0) break;
		
		vector<int> res = my_ask(st);
		if(res[0] + res[1] != bad) goto back;
		
		x = st;
		v = res;
	}
	
	for(auto i:ans) {
		vector<int> res = my_ask(i);
		if(res[0] == 0 && res[1] == 0) return i;
	}
	assert(0);
}

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