void quick(int l,int r, int a[])

{

if (l<r)

{

int i,j,x,tg;

x=a[(l+r)/2];

i=l;

j=r;

while (i<=j)

{

while (a[i]<x)

i++;

while (a[j]>x)

j--;

if (i<=j)

{

tg=a[i];

a[i]=a[j];

a[j]=tg;

i++;

j--;

}

}

quick(l,j,a);

quick(i,r,a);

}

}