Submission #1307489

#	Time	Username	Problem	Language	Result	Execution time	Memory
1307489		hectormedrano	Arranging Shoes (IOI19_shoes)	C++20	45 / 100	98 ms	80532 KiB

shoes

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

vector<ll> st(8e5+5, 0);

void update(ll l, ll r, ll ind, ll pos){
    if(l == r){st[ind]++; return;}
    ll m = (l+r)/2;
    if(pos<=m){
        update(l, m, 2*ind, pos);
    } else {
        update(m+1, r, 2*ind+1, pos);
    }
    st[ind] = st[2*ind] + st[2*ind+1];
}

ll query(ll l, ll r, ll ind, ll ql, ll qr){
    if(r<ql or qr<l){return 0;}
    if(ql<=l and r<=qr){return st[ind];}
    ll m = (l+r)/2;
    return query(l, m, 2*ind, ql, qr) + query(m+1, r, 2*ind+1, ql, qr);
}

ll count_swaps(vector<int> s) {
    ll inv = 0;
    ll n = s.size();
    n = n/2;
    vector<pair<ll, ll>> a;
    vector<queue<ll>> q(n+1);
    for(ll i=0;i<2*n;i++){
        if(s[i]<0){
            a.push_back({s[i], i});
            a.push_back({-s[i], -1});
        } else {
            q[s[i]].push(i);
        }
    }
    for(ll i=0;i<2*n;i++){
        if(a[i].first > 0){
            a[i].second = q[a[i].first].front();
            q[a[i].first].pop();
        }
    }
    for(ll i=0;i<2*n;i++){
        inv += query(0, 2*n-1, 1, a[i].second, 2*n-1);
        update(0, 2*n-1, 1, a[i].second);
    }
	return inv;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15