Submission #58422

#	Time	Username	Problem	Language	Result	Execution time	Memory
58422		reality	Ancient Books (IOI17_books)	C++17	12 / 100	3 ms	616 KiB

books

#include "books.h"
#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
#include "books.h"
long long minimum_walk(std::vector<int> p, int s) {
	int n = p.size();
	ll ans = 0;
	while (s < n && p[s] == s)
		++s,ans += 2;
	if (s == n)
		return 0;
	vi was(n,0);
	vector < pii > e;
	for (int i = 0;i < n;++i) 
		if (i != p[i] && !was[i]) {
			int cnt = i;
			int mx = 0;
			do {
				was[cnt] = 1;
				smax(mx,cnt);
				cnt = p[cnt];
			} while (cnt != i);
			e.pb(mp(i,mx));
		}
	for (int i = 0;i < n;++i)
		ans += abs(i - p[i]);
	int k = e.size();
	int j = 0;
	for (int i = 0;i + 1 < k;++i)
		if (e[i + 1].fi > e[i].se)
			ans += 2;
	return ans;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:41:6: warning: unused variable 'j' [-Wunused-variable]
  int j = 0;
      ^

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