"Algorithm design-fast sorting" random fast sorting algorithm

1. Algorithm Flow:

But in order to reduce the algorithm because the initial data may have been partially sorted by size, the complexity of the algorithm turns into O (N2) Random selection method

The complexity of the fast sorting algorithm is reduced by randomly generating (p,r) a number between random_partition and then swapping a[i] with A[r].

Code implementation:

#include <stdio.h>
#include <stdlib.h>
#define DATATYPE INT
void Fastsort (DataType a[], int left, int right);//Quick Sort
int random_partition (DataType a[],int p,int R)
{

int I=rand ()% (r-p+1) +p;
{
int temp=a[i];
A[I]=A[R];
A[r]=a[i];
}
int X=a[r];
int i=p-1;
for (int j=p;j<=r-1;j++)
{
if (a[j]<=x)
{
i=i+1;
{
int temp=a[i];
A[I]=A[J];
A[j]=temp;
}
}
}
{
int temp=a[i+1];
A[I+1]=A[R];
A[r]=temp;
}
return i+1;
}
void Fastsort (DataType a[], int left, int. right)
{
if (left<right)
{
int pivotloc=partition (a,left,right);
Fastsort (a,left,pivotloc-1);
Fastsort (A,pivotloc+1,right);
}
}


DataType Main (void)
{
DataType *a = (DataType *) malloc (sizeof (DataType));
DataType key;
DataType i = 1;
A[0] = 0;
printf ("Please enter the numbers casually, then this program for these numbers from small to large order!" Press # to end \ n ");
while (scanf ("%d", &key) = = 1)
{
A[i] = key;
i++;
}
printf ("The result after sorting is: \ n");
Fastsort (A, 1,i-1);
DataType K;
for (k = 1; k <= i-1; k++)
printf ("%d", a[k]);
return 0;
}

"Algorithm design-fast sorting" random fast sorting algorithm