Submission #704317

#	Time	Username	Problem	Language	Result	Execution time	Memory
704317		firewater	Arranging Shoes (IOI19_shoes)	C++14	Compilation error	0 ms	0 KiB

shoes

#include<queue>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define ll long long
#define N 202300
#include "shoes.h"

using namespace std;

ll n,x,y,ans,c[N],p[N];
queue<ll>d[N];
void add(ll x,ll y)
{
	x++;
	for(;x<=n*2;x+=x&-x)
		c[x]+=y;
	return;
}
ll ask(ll x)
{
	ll sum=0;
	for(;x;x-=x&-x)
		sum+=c[x];
	return sum;
}
long long count_swaps(std::vector<ll> s) {
	n=s.size()/2;
	ans=0;
	for(ll i=2*n-1;i>=0;--i){
		add(i,1);
		x=s[i];
		d[x+n].push(i);
	}
	for(ll i=2*n-1;i>=0;--i){
		if(p[i])continue;
		x=s[i];
		y=-s[i];
		if(x<0)ans++;
		ll j=d[y+n].front();
		d[x+n].pop();
		d[y+n].pop();
		
		ans+=ask(i-1)-ask(j);
		add(j,-1);
		p[j]=1;
	}
	return ans;
}
//int main()
//{
//	vector<ll>aaa;
//	aaa.push_back(2);
//	aaa.push_back(1);
//	aaa.push_back(-1);
//	aaa.push_back(-2);
//	printf("%lld\n",count_swaps(aaa));
//	return 0;
//}

Compilation message (stderr)

/usr/bin/ld: /tmp/cc3iwTtC.o: in function `main':
grader.cpp:(.text.startup+0x29d): undefined reference to `count_swaps(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status