Submission #171623

#	Time	Username	Problem	Language	Result	Execution time	Memory
171623		losmi247	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	56 ms	25564 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5+45;

ll n,a[N];
ll drvo[10*N];

void build(int i,int j,int node){
    if(i == j){
        drvo[node] = 1;
        return;
    }
    int mid = i+(j-i)/2;
    build(i,mid,2*node);
    build(mid+1,j,2*node+1);
    drvo[node] = drvo[2*node]+drvo[2*node+1];
}

void update(int i,int j,int pos,int node){
    if(i == j){
        drvo[node] = 0;
        return;
    }
    int mid = i+(j-i)/2;
    if(pos <= mid){
        update(i,mid,pos,2*node);
    }
    else{
        update(mid+1,j,pos,2*node+1);
    }
    drvo[node] = drvo[2*node]+drvo[2*node+1];
}

ll get(int i,int j,int l,int r,int node){
    if(j < l || i > r){
        return 0;
    }
    if(l <= i && r >= j){
        return drvo[node];
    }
    int mid = i+(j-i)/2;
    return get(i,mid,l,r,2*node)+get(mid+1,j,l,r,2*node+1);
}

set <int> s[2*N];

ll count_swaps(vector <int> v){
    n = v.size();
    for(int i = 1; i <= n; i++){
        a[i] = v[i-1];
    }
    for(int i = 1; i <= n; i++){
        s[a[i]+n].insert(i);
    }
    build(1,n,1);
    ll sol = 0;
    ll id = 1;
    for(int t = 1; t <= n/2; t++){
        ll poz = *s[-a[id]+n].begin();
        s[a[id]+n].erase(id);
        s[-a[id]+n].erase(poz);
        sol += get(1,n,id,poz,1)-2;
        if(a[id] > 0){
            sol++;
        }
        //cout << id << " " << poz << " " << sol << endl;
        update(1,n,id,1);
        update(1,n,poz,1);
        if(poz == id+1){
            id += 2;
        }
        else{
            id++;
        }
    }
    return sol;
}

/*int main(){
    vector <int> v = {-2, 2, 2, -2};
    cout << count_swaps(v) << endl;
}*/

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