Submission #69262

#	Time	Username	Problem	Language	Result	Execution time	Memory
69262		Bruteforceman	Ancient Books (IOI17_books)	C++11	22 / 100	2067 ms	15296 KiB

books

#include "books.h"
#include "bits/stdc++.h"
using namespace std;

long long minimum_walk(std::vector<int> p, int s) {
	bool good = true;
	for(int i = 0; i < p.size(); i++) {
		if(p[i] != i) {
			good = false;
		}
	}
	if(good) return 0;
	int l = 0;
	int r = p.size() - 1;
	long long ans = 0;
	while(l < p.size() && p[l] == l) {
		if(s == l) {
			ans += 2;
			++s;
		}
		++l;
	}
	while(r >= 0 && p[r] == r) {
		if(s == r) {
			ans += 2;
			--s;
		}
		--r;
	}
	for(int i = l; i < r; i++) {
		int go_left = 0;
		int go_right = 0;
		for(int j = l; j <= i; j++) {
			if(p[j] > i) {
				++go_left;
			}
		}
		for(int j = i + 1; j <= r; j++) {
			if(p[j] < i+1) {
				++go_right;
			}
		}
		assert(go_left == go_right);
		ans += max(2, go_left + go_right);
	}
	return ans;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:7:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < p.size(); i++) {
                 ~~^~~~~~~~~~
books.cpp:16:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(l < p.size() && p[l] == l) {
        ~~^~~~~~~~~~

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