Submission #105225

#	Time	Username	Problem	Language	Result	Execution time	Memory
105225		bert30702	Ancient Books (IOI17_books)	C++17	50 / 100	222 ms	12168 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using namespace std;
const int MX = 1e6 + 100;
int G[MX];
long long minimum_walk(vector<int> p, int s) {
	while(p.back() == p.size() - 1 and p.back() != s) p.pop_back();
	int n = p.size();
	long long sum = 0;
	for(int i = 0; i < n; i ++) {
		G[p[i]] = max(G[p[i]], i);
		G[i]    = max(G[i], p[i]);
		sum += abs(i - p[i]);
	}
	for(int i = 0; i + 1 < n; i ++) {
		if(p[i] == i and i < s) continue;
		int ptr = i + 1;
		while(ptr <= G[i]) {
			G[i] = max(G[i], G[ptr]);
			ptr ++;
		}
		if(ptr < n) sum += 2;
		i = ptr - 1;
	}
	return sum;
}
//main () {
//	cout << minimum_walk({2, 3, 0, 1}, 0);
//}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:7:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(p.back() == p.size() - 1 and p.back() != s) p.pop_back();
        ~~~~~~~~~^~~~~~~~~~~~~~~

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