Cod sursa(job #3314099)

Utilizator cont_superscoalaSuperScoala cont_superscoala Data 8 octombrie 2025 12:56:17
Problema Sortare prin comparare Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.58 kb
/*
https://infoarena.ro/problema/algsort
*/
#include <fstream>
#include <cstdlib>

using namespace std;

const int N = 5e5;

int v[N];

void part_3(int v[], int st, int dr, int &p1, int &p2)
{
    int i = st;
    p1 = st;
    p2 = dr - 1;
    while (i <= p2)
    {
        if (v[i] == v[dr])
        {
            i++;
        }
        else if (v[i] < v[dr])
        {
            swap(v[p1++], v[i++]);
        }
        else///v[i] < v[dr]
        {
            swap(v[p2--], v[i]);
        }
    }
    swap(v[++p2], v[dr]);
}

/*
int part_2(int v[], int st, int dr)
{

    int poz = rand() % (dr - st + 1);
    swap(v[dr], v[poz+st]);

    int p = st;
    for (int i = st; i < dr; i++)
    {
        if (v[i] <= v[dr])
        {
            swap(v[p++], v[i]);
        }
    }
    swap(v[p], v[dr]);
    return p;
}
*/

void quick_sort(int v[], int st, int dr)
{
    if (st >= dr)
    {
        return;
    }
    int p1, p2;
    part_3(v, st, dr, p1, p2);
    quick_sort(v, st, p1 - 1);
    quick_sort(v, p2 + 1, dr);
}

void shuffle(int v[], int n)
{
    for (int i = n - 1; i > 0; i--)
    {
        int poz = rand() % (i + 1);
        swap(v[i], v[poz]);
    }
}

int main()
{
    ifstream in("algsort.in");
    ofstream out("algsort.out");
    int n;
    in >> n;
    for (int i = 0; i < n; i++)
    {
        in >> v[i];
    }
    shuffle(v, n);
    quick_sort(v, 0, n - 1);
    for (int i = 0; i < n; i++)
    {
        out << v[i] << " ";
    }
    out << "\n";
    in.close();
    out.close();
    return 0;
}