Submission #117904

#	Time	Username	Problem	Language	Result	Execution time	Memory
117904		PeppaPig	Ancient Books (IOI17_books)	C++14	50 / 100	147 ms	17696 KiB

books

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

#define long long long

using namespace std;

const int N = 1e6+5;

int n;
int qs[N];
long ans;

long minimum_walk(vector<int> p, int s) {
	n = p.size();

	for(int i = 0; i < n; i++) {
		if(i < p[i]) ++qs[i], --qs[p[i]];
		if(i > p[i]) ++qs[p[i]], --qs[i];
		ans += abs(i - p[i]);
	}
	for(int i = 1; i < n; i++) qs[i] += qs[i-1];
	int l = 0, r = n - 2;
	for(int i = 0; i <= s; i++) {
		l = i;
		if(qs[l]) break;
	}
	for(int i = n - 2; i >= s - 1; i--) {
		r = i;
		if(qs[r]) break;
	}
	for(int i = l; i <= r; i++) if(!qs[i]) ans += 2;

	return ans;
}

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