Cod sursa(job #1553573)

Utilizator rptomaToma Radu-Petrescu rptoma Data 20 decembrie 2015 01:31:52
Problema Statistici de ordine Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
#include <fstream>
#include <ctime>
#include <cstdlib>
using namespace std;
int c[30000001];

ifstream f("sdo.in");
ofstream g("sdo.out");

int partitie(int st, int dr){
    int pindex,i,y;
    y=st+(rand()%(dr-st+1));
    swap(c[y],c[dr]);
    pindex=st;
    for(i=st;i<=dr-1;i++){
        if(c[i]<=c[dr]){
            swap(c[i],c[pindex]);
            pindex++;
        }
    }
    swap(c[dr], c[pindex]);
    return pindex;
}

int quickSelect(int st, int dr, int k){
    int index;
    index=partitie(st,dr);
    if(k==index) return index;
    else if(k<index) return quickSelect(st, index-1, k);
    else return quickSelect(index+1, dr, k);
}

int main() {
    int i,n,k;
    f>>n>>k;
    for(i=1;i<=n;i++) f>>c[i];
    g<<c[quickSelect(1, n, k)];
    f.close();
    g.close();
    return 0;
}