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  1. Quicksort In-Place
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Quicksort In-Place

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151 Discussions

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  • vutruongminh6d
     + 0 comments

    anyone can explain why this code is wrong import java.io.; import java.util.;

    public class Solution {

    public void swap(int[] a, int i, int j) {
    int tmp = a[i];
    a[i] = a[j];
    a[j] = tmp;
}

public void print(int[] a) {
    for (int i : a) {
        System.out.print(i + " ");
    }
    System.out.print('\n');
}

  public int partition(int[] arr, int left, int right) {
    int pivot = right;
    while (left < right) {
        while (left < right && arr[left] <= arr[pivot]) {
            left++;
        }
        while (left < right && arr[right] >= arr[pivot]) {
            right--;
        }
        swap(arr, left, right);
    }
    swap(arr, pivot, left);
    print(arr);
    return left;
}

public void quickSort(int[] a, int left, int right) {
    if (left >= right) {
        return;
    }
    int pivot = partition(a, left, right);
    quickSort(a, left, pivot - 1);
    quickSort(a, pivot + 1, right);
}

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int[] a = new int[n];
    for (int i = 0; i < n; i++) {
        a[i] = sc.nextInt();
    }
    sc.close();
    new Solution().quickSort(a, 0, a.length - 1);
}

    }

  • berkhel
     + 0 comments

    I received no points for my submission. Instead, I got this message, "We couldn't process your submission. Please submit your code again."

  • thinhproee
     + 0 comments
    import java.util.Scanner;

public class QuickSortInPlace {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = scanner.nextInt();
        }

        quickSort(arr, 0, n - 1);

        scanner.close();
    }

    public static void quickSort(int[] arr, int low, int high) {
        if (low < high) {
            int pivotIndex = partition(arr, low, high);
            printArray(arr);

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

    public static int partition(int[] arr, int low, int high) {
        int pivot = arr[high];
        int i = low - 1;

        for (int j = low; j < high; j++) {
            if (arr[j] < pivot) {
                i++;
                swap(arr, i, j);
            }
        }

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

    public static void swap(int[] arr, int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }

    public static void printArray(int[] arr) {
        for (int num : arr) {
            System.out.print(num + " ");
        }
        System.out.println();
    }
}

  • Masquerade_101
     + 0 comments

    why i didn't got points for this problem

  • homerogazze1015
     + 0 comments

    Does anyone know why this code is gives me an "RangeError: Maximum call stack size exceeded"?

    I have tried the code on many other platforms and it works, but here I get that error...

    function processData(arr) {
  //Enter your code here
  const pivot = arr.length - 1;
  let i = -1;
  
  if(arr.length <= 1) return arr

  for (let j = 0; j < arr.length; j++) {
    
    if (arr[j] < arr[pivot]) {
      //we increment i
      i++;

      //we swamp elements
      const toSwamp = arr[i];
      arr[i] = arr[j];
      arr[j] = toSwamp;
     
    }

    if (j === pivot) {
      const toSwamp = arr[i + 1];
      arr[i + 1] = arr[pivot];
      arr[pivot] = toSwamp;
    
    }
  }
  
  console.log(arr)
  return processData(arr.slice(0, i+1)).concat(processData(arr.slice(i+1, pivot+1)))
}