Cod sursa(job #838015)

Utilizator sebii_cSebastian Claici sebii_c Data 18 decembrie 2012 21:48:34
Problema Sortare prin comparare Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <cstdio>
#include <cstdlib>
#include <ctime>

#include <iostream>

using namespace std;

const int MAXN = 500001;
int A[MAXN];

inline void swap(int i, int j)
{
    int aux = A[i];
    A[i] = A[j];
    A[j] = aux;
}

int partition(int left, int right, int val)
{
    int i = left - 1, j = right;
    for (;;) {
        while (A[++i] < val);
        while (val < A[--j]) if (j == left) break;
        if (i >= j) break;
        swap(i, j);
    }

    return i;
}

void quicksort(int left, int right)
{
    if (left >= right)
        return;
    int rpos = left + (rand() % (right - left + 1));
    swap(right, rpos);
    int p = partition(left, right, A[right]);
    swap(right, p);
    quicksort(left, p - 1);
    quicksort(p + 1, right);
}

int main()
{
    srand(time(NULL));
    freopen("algsort.in", "r", stdin);
    freopen("algsort.out", "w", stdout);

    int n;
    cin >> n;
    for (int i = 0; i < n; ++i)
        cin >> A[i];
    quicksort(0, n - 1);
    for (int i = 0; i < n - 1; ++i)
        cout << A[i] << " ";
    cout << A[n - 1] << "\n";

    return 0;
}