제출 #54210

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
54210		radoslav11	고대 책들 (IOI17_books)	C++14	70 / 100	287 ms	59676 KiB

books

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

using namespace std;
template<class T, class T2> inline int chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline int chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
const int MAXN = (1 << 20);

int n;
int p[MAXN];
bool used[MAXN];

pair<int, int> dfs(int u)
{
	used[u] = true;
	pair<int, int> ret = {u, u};

	if(!used[p[u]])
	{
		pair<int, int> oth = dfs(p[u]);
		chkmax(ret.second, oth.second);
		chkmin(ret.first, oth.first);
	}

	return ret;
}

int L, R;
int mn[1 << 10][1 << 10];
int mx[1 << 10][1 << 10];
int dp[1 << 10][1 << 10];

int Min(int l, int r)
{
	if(l == r) return p[l];
	int &memo = mn[l][r];
	if(memo != -1) return memo;
	return memo = min(Min(l + 1, r), Min(l, r - 1));
}

int Max(int l, int r)
{
	if(l == r) return p[l];
	int &memo = mx[l][r];
	if(memo != -1) return memo;
	return memo = max(Max(l + 1, r), Max(l, r - 1));
}

int rec(int l, int r)
{
	if(l == L && r == R)
		return 0;

	int &memo = dp[l][r];
	if(memo != -1) return memo;

	int nl = Min(l, r);
	if(nl < l) return memo = rec(nl, r);
	
	int nr = Max(l, r);
	if(r < nr) return memo = rec(l, nr);
	

	memo = (int)1e9;
	if(L < l) chkmin(memo, rec(l - 1, r) + 2);
	if(r < R) chkmin(memo, rec(l, r + 1) + 2);

	return memo;
}

long long minimum_walk(std::vector<int> p, int s) 
{
	n = p.size();
	for(int i = 0; i < n; i++)
		::p[i] = p[i];

	int64_t answer = 0;
	for(int i = 0; i < n; i++)
		answer += abs(i - p[i]);

	vector<pair<int, int> > li;
	for(int i = 0; i < n; i++)
		if(i != p[i] && !used[i])
			li.push_back(dfs(i));				
	li.push_back({s, s});

	sort(li.begin(), li.end());
	
	vector<pair<int, int> > tmp;
	for(int i = 0; i < (int)li.size(); i++)
		if(tmp.empty() || tmp.back().second < li[i].first) tmp.push_back(li[i]);
		else chkmax(tmp[tmp.size() - 1].second, li[i].second);

	li = tmp;

	int last = li[0].first;
	for(auto it: li)
	{
		answer += 2 * (it.first - last);
		last = it.second;
	}

	if(s != 0)
	{
		int l, r;
		for(auto it: li)
			if(it.first <= s && s <= it.second)
				l = it.first, r = it.second;
		
		memset(mn, -1, sizeof(mn));
		memset(mx, -1, sizeof(mx));

		::L = l;
		::R = r;
	
		memset(dp, -1, sizeof(dp));
		answer += rec(s, s);
	}

	return answer;
}

컴파일 시 표준 에러 (stderr) 메시지

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:115:7: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
   ::R = r;
   ~~~~^~~
books.cpp:114:7: warning: 'l' may be used uninitialized in this function [-Wmaybe-uninitialized]
   ::L = l;
   ~~~~^~~

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