Submission #766011

#	Time	Username	Problem	Language	Result	Execution time	Memory
766011		marvinthang	Ancient Books (IOI17_books)	C++17	50 / 100	82 ms	8716 KiB

books

/*************************************
*    author: marvinthang             *
*    created: 25.06.2023 13:04:25    *
*************************************/

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

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i--; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
    #include "debug.h"
#else
    #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
    #define DB(...) 23
    #define db(...) 23
    #define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <class A, class B> bool minimize(A &a, B b)  { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b)  { if (a < b) { a = b; return true; } return false; }

// end of template

long long minimum_walk(vector<int> p, int s) {
	long long res = 0;
	int n = p.size();
	REP(i, n) res += abs(i - p[i]);
	int last = n - 1;
	while (last >= s && p[last] == last) --last;
	int first = 0;
	while (first <= s && p[first] == first) ++first;
	int l = p[s], r = p[s], i = s, j = s;
	int cnt_l = 0, cnt_r = 0;
	while (first < i || j < last) {
		if (l < i || j < r) {
			while (l < i || j < r) {
				while (l < i) {
					--i;
					if (p[i] > r) {
						res += cnt_l;
						cnt_l = cnt_r = 0;
					}
					minimize(l, p[i]);
					maximize(r, p[i]);
				}
				while (j < r) {
					++j;
					if (p[j] < l) {
						res += cnt_r;
						cnt_l = cnt_r = 0;
					}
					minimize(l, p[j]);
					maximize(r, p[j]);
				}
			}
		} else {
			if (first < l) {
				cnt_l += 2;
				--l;
			}
			if (r < last) {
				cnt_r += 2;
				++r;
			}
		}
	}
	return res + cnt_l + cnt_r;
}

#ifdef LOCAL
#include "books.h"

#include <cstdio>
#include <vector>
#include <cassert>

using namespace std;

int main() {
	file("books");
	int n, s;
	assert(2 == scanf("%d %d", &n, &s));

	vector<int> p((unsigned) n);
	for(int i = 0; i < n; i++)
		assert(1 == scanf("%d", &p[(unsigned) i]));

	long long res = minimum_walk(p, s);
	printf("%lld\n", res);

	return 0;
}
#endif

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