Submission #441485

#	Time	Username	Problem	Language	Result	Execution time	Memory
441485		QuantumK9	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	1092 ms	146460 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
 
using namespace std;
 
#define ll long long
#define pb push_back
#define mp make_pair
 
map<int, queue<int> > rgt;
 
long long count_swaps(vector<int> s) {
	//nums
	ll n = s.size()/2;
	ll S = s.size();
 
	//iterate through s -- preprocess
	for( int i = 0; i < S; i++ ){
		rgt[ s[i] ].push(i);
	}
 
	bool idim[S];
	memset( idim, true, sizeof idim );
 
	//process
	ll grand = 0;
	for( int i = 0; i < S; i++ ){
 
		if( idim[i] ){
 
			idim[i] = false;
			rgt[ s[i] ].pop();
 
			//move partner 
			ll val = rgt[ -s[i] ].front();
			for( int j = 0; j < val; j++ ){ grand += idim[j]; }
			idim[val] = false;
			rgt[ -s[i] ].pop();
 
			if( s[i] > 0 ){ grand++; }
		}
 
	}	
 
	return grand;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:14:5: warning: unused variable 'n' [-Wunused-variable]
   14 |  ll n = s.size()/2;
      |     ^

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