Submission #799174

#	Time	Username	Problem	Language	Result	Execution time	Memory
799174		LittleCube	Ancient Books (IOI17_books)	C++17	50 / 100	114 ms	26600 KiB

books

#include "books.h"
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
using namespace std;

// PixelCat was here for a night ;)
// and mango is incredibly orz

int dp[1000005], a[1000005], b[1000005], last;

long long minimum_walk(std::vector<int> p, int s)
{
	int n = p.size();
	ll ans = 0;
	for (int i = 0; i < n; i++)
	{
		ans += abs(p[i] - i);
		a[i] = p[i];
		b[p[i]] = i;
	}
	for (int i = 0; i < n; i++)
		a[i] = max({i, a[i], b[i]});
	for (int i = 1; i < n; i++)
		a[i] = max(a[i - 1], a[i]);
	last = n - 1;
	while (p[last] == last)
		last--;
	dp[0] = 0;
	for (int i = 1; i < n; i++)
		dp[i] = 1e9;
	for (int i = 0; i < n; i++)
	{
		dp[i + 1] = min(dp[i + 1], dp[i] + 2);
		dp[a[i]] = min(dp[a[i]], dp[i]);
	}
	return ans + dp[last];
}

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