Submission #112335

#	Time	Username	Problem	Language	Result	Execution time	Memory
112335		updown1	Ancient Books (IOI17_books)	C++17	50 / 100	269 ms	32680 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define For(i, a, b) for(int i=a; i<b; i++)
#define ffi For(i, 0, N)
#define ffj For(j, 0, M)
#define ffa ffi ffj
//#define s <<" "<<
#define c <<" : "<<
#define w cout
#define e "\n"
#define pb push_back
#define mp make_pair
#define a first
#define b second
//#define int ll
const int MAXN = 1000000;
//Global Variables
ll N, out = 0, loc[MAXN], comp[MAXN], at = 0;
///             element ,   element
pair<int, int> rng[MAXN];
///                comp
bool vis[MAXN], del[MAXN];
///   element ,     comp

void go1(int at, int co) {
	if (comp[at] != -1) return;
	rng[co].a = min(rng[co].a, at);
	rng[co].b = max(rng[co].b, at);
	comp[at] = co;
	out += abs(loc[at]-at);
	go1(loc[at], co);
}
void go(int at) {
	if (vis[at]) return;
	vis[at] = true;
	go(loc[at]);
}

ll minimum_walk(vector<int> p, int s) {
	N = p.size();
	ffi {rng[i] = mp(N, -1); comp[i] = -1; loc[i] = p[i];}
	ffi if (comp[i] == -1) {
		go1(i, at);
		at++;
	}
	//w<< "from components: " << out<<e;
	sort(rng, rng+at);
	int far = -1;
	For (i, 0, at) if (rng[i].a >= s) {
		if (rng[i].a < far) {
			//w<<"deleting"<<e;
			del[comp[rng[i].a]] = true;
        }
		far = max(far, rng[i].b);
	}
	//ffi w<< i c del[comp[i]]<<e;
	far = N+1;
	for (int i=at-1; i>=0; i--) if (rng[i].b <= s) {
		if (rng[i].b > far) {
			//w<<"deleting"<<e;
			del[comp[rng[i].a]] = true;
        }
		far = min(far, rng[i].a);
	}
	//ffi w<< i c del[comp[i]]<<e;
	ffi if (loc[i] == i) del[comp[i]] = true;
	bool moved = false;
	far = s;
	For (i, 0, at) if (rng[i].a >= s) {
	    if (!del[comp[rng[i].a]]) {
            out += 2*(rng[i].a - far);
            moved = true;
	    }
		if (loc[rng[i].b] != rng[i].b) far = max(far, rng[i].b);
		//w<< out<<e;
	}
	far = s;
	for (int i=at-1; i>=0; i--) if (rng[i].b <= s) {
	    if (!del[comp[rng[i].a]]) {
            out += 2*(far - rng[i].b);
            moved = true;
	    }
		if (loc[rng[i].b] != rng[i].b) far = min(far, rng[i].a);
		//w<< out<<e;
	}
	//w<< "moved: " << moved c out<<e;
	if (moved) return out;
	/// find closest location to s that isn't deleted
	int dist = N+1;
	ffi if (!del[comp[i]]) {
        dist = min(dist, abs(s-i));
	}
	if (dist == N+1) dist = 0;
	return out + 2*dist;
}

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