Question

write a program for Merge sort in c & python

Comments

https://onlinegdb.com/sSBSgQHFJ

Answer 1

#include <stdio.h>     void Merge(int arr[], int left, int mid, int right) {
    int i, j, k;
    int n1 = mid - left + 1;
    int n2 = right - mid;
     int Left[n1], Right[n2];
 
    for (i = 0; i <n1; i++)
        Left[i] = arr[left + i];
 
    for (j = 0; j < n2; j++)
        Right[j] = arr[mid + 1 + j];
    i = 0;	 
    j = 0; 
    k = left;  
    while (i < n1 && j < n2)
    {
        if (Left[i] <= Right[j])
        {
            arr[k] = Left[i];
            i++;
        }
        else
        {
            arr[k] = Right[j];
            j++;
        }
        k++;
    }
     while (i < n1)
    {
        arr[k] = Left[i];
        i++;
        k++;
    }
 
    while (j < n2)
    {
        arr[k] = Right[j];
        j++;
        k++;
    } }    void Merge_Sort(int arr[], int left, int right) {
    if (left < right)
    {
 
        int mid = (left+right) / 2;
 
       Merge_Sort(arr, left, mid);
      Merge_Sort(arr, mid + 1, right);
     Merge(arr, left, mid, right);
    } }    int main() {
    int n;  printf("Merge Sort  \n");
      
    printf("Enter the number of elements : ");
    scanf("%d", &n);
 
    int arr[n];
    printf("Enter the elements of array: ");
    for (int i = 0; i < n; i++)
    {
        scanf("%d", &arr[i]);
    }
 
    Merge_Sort(arr, 0, n - 1);
 
    printf("The sorted array is: ");
    for (int i = 0; i < n; i++)
    {
        printf("%d ", arr[i]);
    }
    printf("\n");
    return 0; }

Answer 2

#include <stdio.h>
#include <stdlib.h>


void merge(int arr[], int l, int m, int r)
{
    int i, j, k;
    int n1 = m - l + 1; // getting size of n1 middle - lowest(left) + 1 ;
    int n2 = r - m; // vice vetrsa for n2


    int L[n1], R[n2];


    for (i = 0; i < n1; i++) // for loop added to get numbbers less than count of n1
        L[i] = arr[l + i];
    for (j = 0; j < n2; j++) // repeat telecast
        R[j] = arr[m + 1 + j];


    i = 0; // Initial index of first subarray
    j = 0; // Initial index of second subarray
    k = l; // Initial index of merged subarray
    while (i < n1 && j < n2)
    {
        if (L[i] <= R[j])
        {
            arr[k] = L[i];
            i++;
        }
        else
        {
            arr[k] = R[j];
            j++;
        }
        k++;
    }

    while (i < n1)
    {
        arr[k] = L[i];
        i++;
        k++;
    }

    while (j < n2)
    {
        arr[k] = R[j];
        j++;
        k++;
    }
}

void mergeSort(int arr[], int l, int r)
{
    if (l < r)
    {
        int m = l + (r - l) / 2;
        mergeSort(arr, l, m);
        mergeSort(arr, m + 1, r);

        merge(arr, l, m, r);
    }
}

void printArray(int A[], int size)
{
    int i;
    for (i = 0; i < size; i++)
        printf("%d ", A[i]);
    printf("\n");
}


int main()
{
    int arr[] = {12, 11, 13, 5, 6, 7};
    int arr_size = sizeof(arr) / sizeof(arr[0]);

    printf("%d\n", sizeof(arr));
    printf("%d\n", sizeof(arr[0]));

    printf("Given array is \n");
    printArray(arr, arr_size);

    mergeSort(arr, 0, arr_size - 1);

    printf("\nSorted array is \n");
    printArray(arr, arr_size);
    return 0;
}