Submission #144531

#	Time	Username	Problem	Language	Result	Execution time	Memory
144531		MohamedAhmed04	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	3 ms	380 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>

using namespace std ;

const int MAX = 1e5 + 10 ;

int tree[4 * MAX] ;

void update(int node , int l , int r , int idx)
{
	if(idx > r || idx < l)
		return ;
	if(l == r)
	{
		tree[node] = 1; 
		return ;
	}
	int mid = (l + r) >> 1 ;
	update(node << 1 , l, mid, idx) ;
	update(node << 1 | 1 , mid + 1 ,r  , idx) ;
	tree[node] = tree[node << 1] + tree[node << 1 | 1] ;
}

int query(int node , int l , int r , int from , int to)
{
	if(from > r || to < l)
		return 0;
	if(l >= from && r <= to)
		return tree[node] ;
	int mid = (l + r) >> 1 ;
	int a = query(node << 1 , l , mid , from , to) ;
	int b = query(node << 1 | 1 , mid + 1 , r , from , to) ;
	return (a + b) ;
}

long long count_swaps(vector<int> v) 
{
	int ans = 0 ;
	map<int, int>mp ;
	int n = v.size() ;
	int nxt[n], done[n];
	memset(done, 0, sizeof(done)) ;
	for(int i = n-1 ; i >= 0 ; --i)
	{
		mp[v[i]] = i ;
		if(mp[-v[i]] == 0)
			continue ;
		nxt[i] = mp[-v[i]] ;
	}
	for(int i = 0 ; i < v.size() ; ++i)
	{
		if(done[i])
			continue ;
		done[nxt[i]] = 1 ;
		ans += (nxt[i] - i - 1) ;
		if(v[i] > 0)
			ans++ ;
		ans -= query(1 , 1 , n , i+1, nxt[i]+1) ;
		update(1 , 1 , n , nxt[i] + 1) ;
	}
	return ans ;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:51:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0 ; i < v.size() ; ++i)
                  ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15