Answers for "quick sort"

quick sort program in c

#include<stdio.h>
void quicksort(int number[25],int first,int last){
   int i, j, pivot, temp;

   if(first<last){
      pivot=first;
      i=first;
      j=last;

      while(i<j){
         while(number[i]<=number[pivot]&&i<last)
            i++;
         while(number[j]>number[pivot])
            j--;
         if(i<j){
            temp=number[i];
            number[i]=number[j];
            number[j]=temp;
         }
      }

      temp=number[pivot];
      number[pivot]=number[j];
      number[j]=temp;
      quicksort(number,first,j-1);
      quicksort(number,j+1,last);

   }
}

int main(){
   int i, count, number[25];

   printf("How many elements are u going to enter?: ");
   scanf("%d",&count);

   printf("Enter %d elements: ", count);
   for(i=0;i<count;i++)
      scanf("%d",&number[i]);

   quicksort(number,0,count-1);

   printf("Order of Sorted elements: ");
   for(i=0;i<count;i++)
      printf(" %d",number[i]);

   return 0;
}

quicksort

// @see https://www.youtube.com/watch?v=es2T6KY45cA&vl=en
// @see https://www.youtube.com/watch?v=aXXWXz5rF64
// @see https://www.cs.usfca.edu/~galles/visualization/ComparisonSort.html

function partition(list, start, end) {
    const pivot = list[end];
    let i = start;
    for (let j = start; j < end; j += 1) {
        if (list[j] <= pivot) {
            [list[j], list[i]] = [list[i], list[j]];
            i++;
        }
    }
    [list[i], list[end]] = [list[end], list[i]];
    return i;
}

function quicksort(list, start = 0, end = undefined) {
    if (end === undefined) {
        end = list.length - 1;
    }
    if (start < end) {
        const p = partition(list, start, end);
        quicksort(list, start, p - 1);
        quicksort(list, p + 1, end);
    }
    return list;
}

quicksort([5, 4, 2, 6, 10, 8, 7, 1, 0]);

quicksort

//last element selected as pivot
#include <iostream>

using namespace std;
void swap(int*,int*);
int partition(int arr[],int start,int end)
{
    int pivot=arr[end];
    int index=start;
    int i=start;
    while(i<end)
    {
        if(arr[i]<pivot)
        {
            swap(&arr[index],&arr[i]);
            index++;
        }
        i++;
    }
    swap(&arr[end],&arr[index]);
    return index;
}
void quicksort(int arr[],int start,int end)
{
    if(start<end)
    {
      int pindex=partition(arr,start,end);
      quicksort(arr,start,pindex-1);
      quicksort(arr,pindex+1,end);
    }
}
void display(int arr[],int n)
{
    for(int i=0;i<n;i++)
    {
        cout<<arr[i]<<" ";
    }
    cout<<endl;
}

int main()
{
    int n;
    cout<<"enter the size of the array:"<<endl;
    cin>>n;
    int arr[n];
    cout<<"enter the elements of the array:"<<endl;
    for(int i=0;i<n;i++)
    {
        cin>>arr[i];
    }
    cout<<"sorted array is:"<<endl;
    quicksort(arr,0,n-1);
    display(arr,n);

    return 0;
}
void swap(int *a,int*b)
{
    int temp=*a;
    *a=*b;
    *b=temp;
}

quick sort

#include<stdio.h>
int partition(int arr[], int low, int high) {
  int temp;
  int pivot = arr[high];
  int i = (low - 1); 
  for (int j = low; j <= high - 1; j++) {
    if (arr[j] <= pivot) { 
      i++; 
      temp = arr[i];
      arr[i] = arr[j];
      arr[j] = temp;
    } 
  } 
  temp = arr[i + 1];
  arr[i + 1] = arr[high];
  arr[high] = temp;
  return (i + 1); 
} 
void quick_sort(int arr[], int low, int high) { 
  if (low < high) {
    int pi = partition(arr, low, high); 
    quick_sort(arr, low, pi - 1); 
    quick_sort(arr, pi + 1, high); 
  } 
} 
int print(int arr[], int n) {
  for(int i = 0; i < n; i++) {
    printf("%d ", arr[i]);
  }
}

int main()
{
int n, i;
scanf("%d", &n);
int arr[n];
for(i = 0; i < n; i++)
{
scanf("%d", &arr[i]);
}
quick_sort(arr, 0, n - 1);
print(arr, n);
}

quick sort

//I Love Java
import java.io.*;
import java.util.*;
import java.util.stream.*;
import static java.util.Collections.*;

import static java.util.stream.Collectors.*;

public class Quick_Sort_P {

    static void swap(List<Integer> arr, int i, int j) {
        int temp = arr.get(i);
        arr.set(i, arr.get(j));
        arr.set(j, temp);
    }

    static int partition(List<Integer> arr, int low, int high) {

        int pivot = arr.get(high);
        int i = (low - 1);

        for (int j = low; j <= high - 1; j++) {

            if (arr.get(j) < pivot) {

                i++;
                swap(arr, i, j);
            }
        }
        swap(arr, i + 1, high);
        return (i + 1);
    }

    static void quickSort(List<Integer> arr, int low, int high) {
        if (low < high) {

            int pi = partition(arr, low, high);

            quickSort(arr, low, pi - 1);
            quickSort(arr, pi + 1, high);
        }
    }

    public static void main(String[] args) throws IOException {

        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));

        List<Integer> arr = Stream.of(buffer.readLine().replaceAll("\\s+$", "").split(" ")).map(Integer::parseInt)
                .collect(toList());

        int n = arr.size();

        quickSort(arr, 0, n - 1);
        System.out.println("Sorted array: ");
        System.out.println(arr);
    }
}

quick sort

void swap(int* a, int* b)
{
    int t = *a;
    *a = *b;
    *b = t;
}
 
/* This function takes last element as pivot, places
the pivot element at its correct position in sorted
array, and places all smaller (smaller than pivot)
to left of pivot and all greater elements to right
of pivot */
int partition (int arr[], int low, int high)
{
    int pivot = arr[high]; // pivot
    int i = (low - 1); // Index of smaller element and indicates the right position of pivot found so far
 
    for (int j = low; j <= high - 1; j++)
    {
        // If current element is smaller than the pivot
        if (arr[j] < pivot)
        {
            i++; // increment index of smaller element
            swap(&arr[i], &arr[j]);
        }
    }
    swap(&arr[i + 1], &arr[high]);
    return (i + 1);
}
 
/* The main function that implements QuickSort
arr[] --> Array to be sorted,
low --> Starting index,
high --> Ending index */
void quickSort(int arr[], int low, int high)
{
    if (low < high)
    {
        /* pi is partitioning index, arr[p] is now
        at right place */
        int pi = partition(arr, low, high);
 
        // Separately sort elements before
        // partition and after partition
        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}
 
/* Function to print an array */
void printArray(int arr[], int size)
{
    int i;
    for (i = 0; i < size; i++)
        cout << arr[i] << " ";
    cout << endl;
}
 
// Driver Code
int main()
{
    int arr[] = {10, 7, 8, 9, 1, 5};
    int n = sizeof(arr) / sizeof(arr[0]);
    quickSort(arr, 0, n - 1);
    cout << "Sorted array: \n";
    printArray(arr, n);
    return 0;
}