Submission #339412

#	Time	Username	Problem	Language	Result	Execution time	Memory
339412		Kerim	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	112 ms	20332 KiB

shoes

#include "bits/stdc++.h"
#include "shoes.h"
#define MAXN 200009
#define pb(x) push_back(x)
#define ppb() pop_back()
using namespace std;
int vis[MAXN],F[MAXN];
vector<int>a[MAXN],b[MAXN];
int get(int x){int res=0;for(;x;x-=x&(-x))res+=F[x];return res;}
void upd(int x){for(;x<MAXN;x+=x&(-x))F[x]++;}
long long count_swaps(std::vector<int> s) {
	int n=s.size();long long ans=0;
	for(int i=n-1;i>=0;i--){
		if(s[i]>0)a[s[i]].pb(i);
		else b[-s[i]].pb(i);}
	for(int i=0,j;i<n;i++){
		if(vis[i])continue;
		if(s[i]>0)j=b[s[i]].back();
		else j=a[-s[i]].back();
		a[abs(s[i])].ppb();b[abs(s[i])].ppb();
		ans+=(s[i]>s[j])+j-i-1;vis[j]=1;
		ans-=get(j)-get(i);upd(j);
		//for(int k=i+1;k<j;k++)ans-=vis[k];
	}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