Randomized-Select to find the ith smallest element

// Find the ith smallest element of the array A[p..r]. Using non-recursive programming.
// Input file：void
// Output：Stdout (show on monitor)

int Randomized_Select(char A[],int p,int r,int i)
{
　if(p==r)
　　return A[p];
　int q=Randomized_Partition(A,p,r);
　int k=q-p+1;
　if(i==k) // the pivot is the answer
　　return A[q];
　else if(ii-k);
}

// Using randomized method to find the KEY
int Randomized_Partition(char A[],int p,int r)
{
　int i=rand()%(r-p+1)+p;
　Swap(A,r,i);
　return Partition(A,p,r);
}

// Comparision and divide (1.> KEY 2.<= KEY)
int Partition(char A[],int p,int r)
{
　int x=A[r];
　int i=p-1;
　int j;
　for(j=p;j<=r-1;j++)
　　if(A[j]<=x)
　　　Swap(A,++i,j);
　Swap(A,i+1,r);
　return i+1;
}

// Exchange two elements of the data
void Swap(char A[],int i,int j)
{
　int temp=A[i];
　A[i]=A[j];
　A[j]=temp;
　return;
}