Submission #1047275

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047275		vjudge1	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	33 ms	24016 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"
using namespace std;
#define sp " "
#define endl "\n"
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define LL node * 2
#define RR node * 2 + 1
#define N 300005
#define ll long long

int tree[N], n;
vector<int> lft[N], rgt[N];

void update(int x, int val){
	while(x <= n){
		tree[x] += val;
		int lsb = x & -x;
		x += lsb;
	}
}

int query(int x){
	int ans = 0;
	while(x > 0){
		ans += tree[x];
		int lsb = x & -x;
		x -= lsb;
	}
	return ans;
}


long long count_swaps(vector<int> s) {
	n = s.size();
	vector<pii> ranges;
	for (int i = 1; i <= n; i++){
		if (s[i - 1] < 0) lft[-s[i - 1]].pb(i);
		else rgt[s[i - 1]].pb(i);
	}
	ll ans = 0;
	for (int i = 1; i <= n; i++){
		while(!lft[i].empty()){
			int a = lft[i].back(), b = rgt[i].back();
			if (a > b) ans++, swap(a, b); 
			lft[i].pop_back(), rgt[i].pop_back();
			ranges.pb({a, b});
		}
	}
	sort(ranges.begin(), ranges.end());
	for (auto i : ranges){
		ans += i.nd - i.st - 1 - (query(i.nd) - query(i.st));
		update(i.nd, 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