Submission #1037035

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037035		ALeonidou	Ancient Books (IOI17_books)	C++17	50 / 100	101 ms	30692 KiB

books

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

#define ll long long
#define endl "\n"
#define sz(x) (ll)x.size()
#define F first
#define S second
#define pb push_back
#define INF 1000000000000000000

typedef vector <ll> vi;
typedef pair <ll,ll> ii;
typedef vector <ii> vii;

#define dbg(x) cout<<#x<<": "<<x<<endl;
#define dbg2(x,y) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<endl;
#define dbg3(x,y,z) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<" "<<#z<<": "<<z<<endl;

void printVct(vi &v){
	for (ll i =0; i<sz(v); i++){
		cout<<v[i]<<" ";
	}
	cout<<endl;
}

ll n;
vi p;

vi vis;
void dfs(ll u, ll &r){
	vis[u] =1;
	r = max(r,u);
	ll c = p[u];
	if (!vis[c]) dfs(c,r);
}

long long minimum_walk(vector<int> P, int ss) {
	n = sz(P);
	p.resize(n);
	for (ll i =0; i<n; i++){
		p[i] = P[i];
	}
	ll s = ss;

	ll d = 0;
	for (ll i =0; i<n; i++){
		d += abs(i - p[i]);
	}

	ll b = n-1;
	while (b >= 0 && p[b] == b) b--;

	ll r = 0, e = 0;
	vis.assign(n, 0);
	dfs(0, r);
	for (ll i =0; i<b; i++){
		if (r < i) e++;
		if (!vis[i]) dfs(i, r);
  	}

	ll ans = d + e * 2;
	return ans;
}

/*
4 0
0 2 3 1

4 0
0 2 3 1

4 0
3 2 1 0
*/

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:45:5: warning: unused variable 's' [-Wunused-variable]
   45 |  ll s = ss;
      |     ^

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