Submission #821324

#	Time	Username	Problem	Language	Result	Execution time	Memory
821324		AlphaMale06	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	183 ms	9880 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"
using namespace std;
using ll = long long;
#define mp make_pair
#define F first
#define S second
#define pb push_back

const int N = 200010;
int st[4*N];

void Build(int node, int l, int r){
    if(l>r)return;
    if(l==r){
        st[node]=1;
        return;
    }
    int mid=(l+r)/2;
    Build(2*node+1, l, mid);
    Build(2*node+2, mid+1, r);
    st[node]=st[2*node+1]+st[2*node+2];
}

void Update(int node, int l, int r, int ind, int val){
    if(l>r || l>ind || r<ind)return;
    if(l==r){
        st[node]+=val;
        return;
    }
    int mid=(l+r)/2;
    Update(2*node+1, l, mid, ind, val);
    Update(2*node+2, mid+1, r, ind, val);
    st[node]=st[2*node+1]+st[2*node+2];
}

int Get(int node, int l, int r, int L, int R){
    if(l>r || l>R || r<L)return 0;
    else if(L<=l && R>=r){
        return st[node];
    }
    int mid=(l+r)/2;
    return Get(2*node+1, l, mid, L, R)+Get(2*node+2, mid+1, r, L, R);
}


long long count_swaps(std::vector<int> s) {
	int n=s.size();
    Build(0, 0, n-1);
    ll ans=0;
    set<pair<int, int>, less<pair<int, int>>> skup;
    for(int i=0; i< n; i++){
        if(skup.empty()){
            skup.insert(mp(s[i], i));
            continue;
        }
        auto ptr = skup.lower_bound(mp(-s[i], -1));
        pair<int, int> p=*ptr;
        if(ptr==skup.end()){
            skup.insert(mp(s[i], i));
        }
        else if(p.F != -s[i]){
            skup.insert(mp(s[i], i));
        }
        else{
            if(s[i]<0)ans++;
            ans+=Get(0, 0, n-1, p.S, i);
            ans-=2;
            Update(0, 0, n-1, i, -1);
            Update(0, 0, n-1, p.S, 1);
            skup.erase(skup.find(p));
        }
    }
    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