Submission #105035

#	Time	Username	Problem	Language	Result	Execution time	Memory
105035		bert30702	Ancient Books (IOI17_books)	C++17	0 / 100	35 ms	31616 KiB

books

#include <bits/stdc++.h>
#include "books.h"
#define pii pair<int, int>
#define F first
#define S second
using namespace std;
const int MX = 1e6 + 100;
int boss[MX];
int Find(int u) {
	return boss[u] == u ? u : boss[u] = Find(boss[u]);
}
void merge(int a, int b) {
	boss[Find(a)] = Find(b);
}
priority_queue<int> pq[MX];
long long minimum_walk(vector<int> p, int s) {
	long long sum = 0;
	for(int i = 0; i < p.size(); i ++) boss[i] = i;
	for(int i = 0; i < p.size(); i ++) sum += abs(i - p[i]), merge(i, p[i]);
	vector<pair<int, pii> > E;
	for(int i = 0; i + 1 < p.size(); i ++) {
		if(p[i] == i and i != s) continue;
		int ptr = i + 1;
		if(ptr != s and ptr + 1 < p.size() and p[ptr] == ptr) ptr ++;
		if(Find(ptr) != Find(i)) E.push_back({ptr - i, {i, ptr}});
	}
	sort(E.begin(), E.end());
	for(auto it: E) {
		if(Find(it.S.F) != Find(it.S.S)) {
			merge(it.S.F, it.S.S);
			sum += 2 * it.F;
		}
	}
	return sum;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:18:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < p.size(); i ++) boss[i] = i;
                 ~~^~~~~~~~~~
books.cpp:19:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < p.size(); i ++) sum += abs(i - p[i]), merge(i, p[i]);
                 ~~^~~~~~~~~~
books.cpp:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i + 1 < p.size(); i ++) {
                 ~~~~~~^~~~~~~~~~
books.cpp:24:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(ptr != s and ptr + 1 < p.size() and p[ptr] == ptr) ptr ++;
                   ~~~~~~~~^~~~~~~~~~

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