Submission #123167

#	Time	Username	Problem	Language	Result	Execution time	Memory
123167		SirCeness	Ancient Books (IOI17_books)	C++14	0 / 100	2 ms	376 KiB

books

#include <bits/stdc++.h>

#define pb push_back
#define mp make_pair
#define inside sl<=l&&r<=sr
#define outside r<sl||sr<l
#define inf 1000000009
using namespace std;
typedef long long ll;

int n;
vector<int> arr;
vector<ll> numara;
vector<pair<int, pair<int, int> > > edges;
int num = 0;
vector<pair<ll, ll> > minler;
vector<int> dsu;

int find(int node){
	if (dsu[node] == node) return node;
	int ans = find(dsu[node]);
	return dsu[node] = ans;
}

void unionn(int node1, int node2){
	node1 = find(node1);
	node2 = find(node2);
	if (node1 == node2) return;
	dsu[node1] = node2;
}

ll minimum_walk(vector<int> p, int s){
	arr = p;
	n = p.size();
	numara.resize(n);
	ll ans = 0;
	for (int i = 0; i < n; i++) numara[i] = -1;
	for (int i = 0; i < n; i++){
		if (numara[i] == -1 && p[i] != i){
			int node = i;
			int lmost = node;
			int rmost = node;
			while (numara[node] == -1){
				numara[node] = num;
				node = p[node];
				lmost = min(lmost, node);
				rmost = max(rmost, node);
			}
			num++;
			ans += (2*(rmost-lmost));
		}
	}
	
	int last = -1;
	for (int i = 0; i < n; i++){
		if (numara[i] != -1){
			if (last != -1) edges.pb(mp(i-last, mp(numara[i], numara[last])));
			last = i;
		}
	}
	
	dsu.resize(num);
	for (int i = 0; i < num; i++) dsu[i] = i;
	
	sort(edges.begin(), edges.end());
	
	for (int i = 0; i < edges.size(); i++){
		if (find(edges[i].second.first) != find(edges[i].second.second)){
			ans += edges[i].first;
			unionn(edges[i].second.first, edges[i].second.second);
		}
	}
	
	int mindist = inf;
	for (int i = s; i < n; i++){
		if (numara[i] != -1){
			mindist = min(mindist, i-s);
			break;
		}
	}
	for (int i = s; i >= 0; i--){
		if (numara[i] != -1){
			mindist = min(mindist, s-i);
			break;
		}
	}
	ans += 2*mindist;
	
	return ans;
}

Compilation message (stderr)

books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:67:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < edges.size(); i++){
                  ~~^~~~~~~~~~~~~~

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