# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1152099 | MPG | Arranging Shoes (IOI19_shoes) | C++20 | 0 ms | 0 KiB |
//#pragma GCC optomize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse4.1,sse4.2")
#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define max_heap priority_queue<pair <ll, pair <ll, ll>>>
#define min_heap priority_queue<pair <ll, pair <ll, ll>>, vector<pair <ll, pair <ll, ll>>>, greater<pair <ll, pair <ll, ll>>>>
//#define min_heap priority_queue<ll, vector<ll>, greater<ll>>
#define sariE cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define filE freopen("in.txt", "r", stdin); freopen("out1.txt", "w", stdout);
#define endl '\n'
#define md(a) (a % mod + mod) % mod
#define pb push_back
//cout << vectorprecision(5) << fixed << f;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll const maxn = 2e5 + 123;
ll const inf = 2e18;
ll const loG = 23;
ll const mod = 1e9 + 7;
//ll const mod = 998244353;
ll const sq = 350;
ll power(ll a, ll b, ll mod){if(b==0)return 1;if(b==1)return a;ll x = power(a, b / 2, mod);return (((x * x) % mod) * (b % 2 ? a : 1)) % mod;}
ll n, bit[maxn], ans, cnt = maxn;
queue <ll> chap[maxn], rast[maxn];
bool mark[maxn];
ll sum(ll i){
ll ans = 0;
for (i += 2; i > 0; i -= (i & (-i)))
ans += bit[i];
return ans;
}
void adder(ll i, ll val){
for (i += 2; i <= maxn; i += (i & (-i)))
bit[i] += val;
}
ll summer(ll l, ll r){
return sum(r) - sum(l - 1);
}
ll count_swaps(vector<ll> s){
for (int i = 0; i < s.size(); i++){
if (s[i] > 0){
rast[s[i]].push(i);
}
else
chap[-s[i]].push(i);
}
for (int i = 0; i < s.size(); i++){
if (mark[i])
continue;
mark[i] = 1;
ll j;
if (s[i] < 0){
chap[abs(s[i])].pop();
j = rast[abs(s[i])].front();
rast[abs(s[i])].pop();
}
else{
rast[s[i]].pop();
j = chap[s[i]].front();
chap[s[i]].pop();
}
mark[j] = 1;
ll chand = summer(i, j);
//cout << i << ' ' << j << ' ' << chand << endl;
if (s[i] < 0)
ans += j - i - 1 - chand;
else
ans += j - i - chand;
adder(i, 1);
adder(j, 1);
}
return ans;
}
vector <ll> tmp;
void Solve(){
cin >> n;
for (int i = 1; i < n + 1; i++){
ll x; cin >> x;
tmp.push_back(x);
}
cout << count_swaps(tmp) << endl;
}
int main(){
sariE;// filE;
int test = 1;
//cin >> test;
while (test--) Solve();
return 0;
}