Cod sursa(job #2776285)

Utilizator BlaugranasEnal Gemaledin Blaugranas Data 19 septembrie 2021 10:30:18
Problema Statistici de ordine Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.81 kb
#include<fstream>
#include<ctime>
using namespace std;
ifstream F("sdo.in");
ofstream G("sdo.out");
#define R 10000000
int a[3000001],n,k,i,o;
char r[R];
char N()
{
    if(o==R)
        F.read(r,R),o=0;
    return r[o++];
}
int A()
{
    int x=0;
    char c=N();
    while(c<48)
        c=N();
    while(c>47)
        x=x*10+c-48,c=N();
    return x;
}
int P(int a[],int b,int c)
{
	int i=b-1,j=c+1,p=a[b+(rand()%(c-b+1))],l;
	while(1) {
		for(++i;a[i]<p;++i);
		for(--j;a[j]>p;--j);
		if(i<j)
			l=a[i],a[i]=a[j],a[j]=l;
		else
			return j;
	}
	return 0;
}
void S(int a[],int i,int j,int k)
{
	if(i==j)
		return;
	int q=P(a,i,j),t=q-i+1;
	t>=k?S(a,i,q,k):S(a,q+1,j,k-t);
}
int main()
{
	for(srand(time(NULL)),n=A(),k=A(),i=1;i<=n;++i)
		a[i]=A();
	S(a,1,n,k),G<<a[k];
	return 0;
}