Submission #427465

#	Time	Username	Problem	Language	Result	Execution time	Memory
427465		Tangent	Ancient Books (IOI17_books)	C++17	50 / 100	225 ms	23504 KiB

books

#include "books.h"
#include "bits/stdc++.h"

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vii;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vii> vvii;
typedef vector<vll> vvll;
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;

#define ffor(i, a, b) for (ll i = (a); i < (ll)(b); i++)
#define fford(i, a, b) for (ll i = (a); i > (ll)(b); i--)
#define rep(i, n) ffor(i, 0, n)
#define forin(x, a) for (auto &x: a)
#define all(a) a.begin(), a.end()

long long minimum_walk(std::vector<int> p, int s) {
	int n = p.size();
	vii seen(n);
	vpii segs;
	ll res = 0;
	rep(i, n) {
		if (!seen[i]) {
			seen[i] = true;
			int lo = i, hi = i;
			res += abs(p[i] - i);
			int curr = p[i];
			while (curr != i) {
				lo = min(lo, curr);
				hi = max(hi, curr);
				seen[curr] = true;
				res += abs(curr - p[curr]);
				curr = p[curr];
			}
			if (lo != hi)
				segs.emplace_back(lo, hi + 1);
		}
	}
	sort(all(segs));
	reverse(all(segs));
	if (segs.empty()) return res;
	vpii merged = {segs.back()};
	segs.pop_back();
	while (!segs.empty()) {
		if (segs.back().first < merged.back().second) {
			merged.back().second = max(merged.back().second, segs.back().second);
		} else {
			merged.emplace_back(segs.back());
		}
		segs.pop_back();
	}
	int curr = 0;
	forin(seg, merged) {
		res += 2 * (seg.first - curr);
		curr = seg.second - 1;
	}
	return res;
}

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