Submission #957749

#	Time	Username	Problem	Language	Result	Execution time	Memory
957749		suren	Arranging Shoes (IOI19_shoes)	C++14	50 / 100	17 ms	2000 KiB

shoes

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define mk make_pair
#define S second
#define F first
using namespace std;

long long count_swaps(std::vector<int> a) {
	if( a.size() <= 2000 ){
	
		ll ans = 0, srch;
		for(int i = 0; i < a.size(); i ++ ){
			if( a[i] == 0 )
				continue;
			for(int j = i+1; j < a.size(); j ++ ){
				if( a[j] == -a[i] ){
						ans += j-i;
					if( a[i] < 0 )
						ans --;
					a[j] = 0;
					break;
				}
				if( a[j] == 0 ){
					ans --;
				}
			}
		}
		return ans;
	}
	ll n = a.size()/2;
	ll ans = 0, r = n-1;
	for(int i = 0; i < n; i ++ ){
		ans += r-i-1;
	}
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:14:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |   for(int i = 0; i < a.size(); i ++ ){
      |                  ~~^~~~~~~~~~
shoes.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |    for(int j = i+1; j < a.size(); j ++ ){
      |                     ~~^~~~~~~~~~
shoes.cpp:13:15: warning: unused variable 'srch' [-Wunused-variable]
   13 |   ll ans = 0, srch;
      |               ^~~~

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