Submission #1045338

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045338		beaconmc	Ancient Books (IOI17_books)	C++14	50 / 100	152 ms	43444 KiB

books

#include "books.h"

#include <bits/stdc++.h>

 
typedef long long ll;
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)
 
using namespace std;


long long minimum_walk(vector<int> p, int s) {

	vector<int> q;
	for (auto&i : p)q.push_back(i);
	sort(q.begin(), q.end());
	if (p==q) return 0;
	vector<bool> visited;
	vector<ll> maxis;
	for (auto&i : p) visited.push_back(0), maxis.push_back(-1);

	FOR(i,0,p.size()){
		vector<ll> stuff;
		ll temp = i;
		ll maxi = i;
		if (visited[temp]) continue;
		visited[temp] = 1;
		temp = p[temp];
		stuff.push_back(temp);
		while (temp != i){
			maxi = max(maxi, temp);
			visited[temp] = 1;
			temp = p[temp];
			visited[temp] = 1;
			stuff.push_back(temp);
		}
		for (auto&k : stuff){
			maxis[k] = maxi;
		}
	}


	ll cur = 0;
	ll ans = 0;
	FOR(i,0,p.size()){
		ans += abs(p[i]-i);
	}
	ll hi = p.size()-1;
	while (p[hi]==hi) hi--;




	while (cur < p.size()-1){
		if (cur >= hi) break;
		if (cur == maxis[cur]){
			ans+=2, cur++;
		}
		else{
			FOR(i,cur,maxis[cur]+1){
				cur = max(cur,maxis[i]);
			}
		}
	}


	return ans;

}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:21:12: warning: unused variable 'i' [-Wunused-variable]
   21 |  for (auto&i : p) visited.push_back(0), maxis.push_back(-1);
      |            ^
books.cpp:7:33: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 | #define FOR(i,x,y) for(ll i=x; i<y; i++)
......
   23 |  FOR(i,0,p.size()){
      |      ~~~~~~~~~~~~                
books.cpp:23:2: note: in expansion of macro 'FOR'
   23 |  FOR(i,0,p.size()){
      |  ^~~
books.cpp:7:33: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 | #define FOR(i,x,y) for(ll i=x; i<y; i++)
......
   46 |  FOR(i,0,p.size()){
      |      ~~~~~~~~~~~~                
books.cpp:46:2: note: in expansion of macro 'FOR'
   46 |  FOR(i,0,p.size()){
      |  ^~~
books.cpp:55:13: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |  while (cur < p.size()-1){
      |         ~~~~^~~~~~~~~~~~

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