Submission #519734

#	Time	Username	Problem	Language	Result	Execution time	Memory
519734		WongChun1234	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	277 ms	275088 KiB

shoes

#include "shoes.h"
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

const int MAXN=200050;
int n,pt=0,bit[MAXN],rrl[MAXN];
bool used[MAXN];
queue<int> pos[MAXN],neg[MAXN];
ll ans;
ll query(int num){
	ll ret=0;
	for (int i=num;i;i-=(i&-i)){
		ret+=bit[i];
	}
	return ret;
}
void add(int num){
	for (int i=num;i<=n+1;i+=(i&-i)){
		bit[i]++;
	}
}
long long count_swaps(std::vector<int> s) {
	n=s.size();
	for (int i=0;i<n;i++){
		if (s[i]>0) pos[s[i]].push(i);
		else neg[-s[i]].push(i);
	}
	for (int i=0;i<n;i++){
		if (used[i]) continue;
		rrl[pt++]=neg[abs(s[i])].front();
		used[neg[abs(s[i])].front()]=1;
		neg[abs(s[i])].pop();
		rrl[pt++]=pos[abs(s[i])].front();
		used[pos[abs(s[i])].front()]=1;
		pos[abs(s[i])].pop();
	}
	for (int i=n-1;i>=0;i--){
		ans+=query(rrl[i]+1);
		add(rrl[i]+1);
	}
	return ans;
}

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