Cod sursa(job #1021943)

Utilizator dan.ghitaDan Ghita dan.ghita Data 4 noiembrie 2013 15:02:33
Problema Sortare prin comparare Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<fstream>
#include<ctime>
using namespace std;
ifstream f("algsort.in");
ofstream g("algsort.out");
int v[500000],n;
int pivot(int a, int b)
{
    int p1,p2,p3,p,mini,maxi;
    p1=v[a + rand() % (b-a+1)];
    p2=v[a + rand() % (b-a+1)];
    p3=v[a + rand() % (b-a+1)];
    if(p1<=p2&&p1<=p3)
        mini=p1;
    if(p2<=p1&&p2<=p3)
        mini=p2;
    if(p3<=p1&&p3<=p2)
        mini=p3;
    if(p1>=p2&&p1>=p3)
        maxi=p1;
    if(p2>=p1&&p2>=p3)
        maxi=p2;
    if(p3>=p1&&p3>=p2)
        maxi=p3;
    p=p1+p2+p3-maxi-mini;
    return p;

}
void qs(int a, int b)
{
    int i=a, j=b, piv;
    piv=pivot(a,b);
    while(i<=j)
    {
        while(v[i]<piv)
            ++i;
        while(v[j]>piv)
            --j;
        if(i<=j)
        {
            swap(v[i], v[j]);
            ++i;
            --j;
        }
    }
    if(a<j)
        qs(a,j);
    if(i<b)
        qs(i,b);

}
int main()
{

    f>>n;
    for(int i=0;i<n;++i)
        f>>v[i];
    qs(0,n-1);
    for(int i=0;i<n;++i)
        g<<v[i]<<" ";

    return 0;
}