Submission #1205034

#	Time	Username	Problem	Language	Result	Execution time	Memory
1205034		countless	Ancient Books (IOI17_books)	C++20	0 / 100	0 ms	324 KiB

books

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

typedef long long ll;
typedef long double ld;

const ll MOD = 998244353;
const ll INF = 1e18;
const ld EPS = 1e-12;

#define endl "\n"
#define sp <<" "<<
#define REP(i, a, b) for(ll i = a; i < b; i++)
#define dbg(x) cout << #x << " = " << x << endl
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())

struct custom_hash {
	static uint64_t splitmix64(uint64_t x) {
		// http://xorshift.di.unimi.it/splitmix64.c
		x += 0x9e3779b97f4a7c15;
		x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
		x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
		return x ^ (x >> 31);
	}

	size_t operator()(uint64_t x) const {
		static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
		return splitmix64(x + FIXED_RANDOM);
	}
};

template <typename Key, typename Value>
using hash_map = unordered_map<Key, Value, custom_hash>;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// uniform_int_distribution<int>(a, b)(rng);
// shuffle(all(a), rng);

struct segtree {
	int l, r, cnt;
	segtree *left, *right;

	void merge() {
		cnt = left->cnt + right->cnt;
	}

	segtree(int l, int r, vector<int> &a) : l(l), r(r), cnt(0) {
		if (l == r) {
			left = right = nullptr;
			return;
		}

		int m = (l+r)/2;
		left = new segtree(l, m, a);
		right = new segtree(m+1, r, a);
		merge();
	}

	void update(int ind) {
		if (l == r) {
			cnt = 1;
			return;
		}

		int m = (l+r)/2;
		if (ind <= m) left->update(ind);
		else right->update(ind);
		merge();
	}

	int query(int ql, int qr) {
		if (ql > r or qr < l) {
			return 0;
		}

		if (ql <= l and r <= qr) {
			return cnt;
		}

		return left->query(ql, qr) + right->query(ql, qr);
	}
};

ll minimum_walk(vector<int> p, int s) {
	assert(s == 0);

	int n = p.size();
	int last = 0;
	ll ans = 0;

	segtree st(0, n-1, p);
	vector<int> pos(n);
	REP(i, 0, n) {
		pos[p[i]] = i;
	}

	int cnt = 0;
	REP(i, 0, n) {
		int ele = i, loc = pos[ele];
		if (pos[ele] < n-1) loc += st.query(pos[ele]+1, n-1);
		if (ele != loc) {
			ans += (loc - last);
			ans += (loc - ele);
			cnt++;
			last = ele;
			st.update(pos[ele]);
		}
	}

	ans += last;

	return ans;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 10
• Subtask 3: 0 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30