Answers for "merge sort in c"

merge sort c

#include <stdio.h>

void merge(int arr[], int start, int mid, int end) {

  int len1 = mid - start + 1;
  int len2 = end - mid;

  int leftArr[len1], rightArr[len2];

  for (int i = 0; i < len1; i++)
    leftArr[i] = arr[start + i];
  for (int j = 0; j < len2; j++)
    rightArr[j] = arr[mid + 1 + j];

  int i, j, k;
  i = 0;
  j = 0;
  k = start;

  while (i < len1 && j < len2) {
    if (leftArr[i] <= rightArr[j]) {
      arr[k] = leftArr[i];
      i++;
    } else {
      arr[k] = rightArr[j];
      j++;
    }
    k++;
  }

  while (i < len1) {
    arr[k] = leftArr[i];
    i++;
    k++;
  }

  while (j < len2) {
    arr[k] = rightArr[j];
    j++;
    k++;
  }
}

void mergeSort(int arr[], int start, int end) {
  if (start < end) {

    int mid = start + (end - start) / 2;
    mergeSort(arr, start, mid);
    mergeSort(arr, mid + 1, end);
    merge(arr, start, mid, end);
  }
}

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

int main() {
  int arr[] = {6, 5, 12, 10, 9, 1};
  int size = sizeof(arr) / sizeof(arr[0]);
  
  printf("Original arrayn");
  display(arr, size);
  
  mergeSort(arr, 0, size - 1);

  printf("Sorted arrayn");
  display(arr, size);
}

Merge sort in c++

#include <iostream>
using namespace std;
 

void merge(int arr[], int l, int m, int r)
{
    int n1 = m - l + 1;
    int n2 = r - m;
 
 
    int L[n1], R[n2];
 
   
    for (int i = 0; i < n1; i++)
        L[i] = arr[l + i];
    for (int j = 0; j < n2; j++)
        R[j] = arr[m + 1 + j];

 
    int i = 0;
 
    
    int j = 0;
 
    
    int k = l;
 
    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){
        return;
    }
    int m = (l+r-1)/2;
    mergeSort(arr,l,m);
    mergeSort(arr,m+1,r);
    merge(arr,l,m,r);
}
 

void printArray(int A[], int size)
{
    for (int i = 0; i < size; i++)
        cout << A[i] << " ";
}
 

int main()
{
    int arr[] = { 12, 11, 13, 5, 6, 7 };
    int arr_size = sizeof(arr) / sizeof(arr[0]);
 
    cout << "Given array is n";
    printArray(arr, arr_size);
 
    mergeSort(arr, 0, arr_size - 1);
 
    cout << "nSorted array is n";
    printArray(arr, arr_size);
    return 0;
}

sorting array in c

#include <stdio.h>
    void main()
    {
 
        int i, j, a, n, number[30];
        printf("Enter the value of N n");
        scanf("%d", &n);
 
        printf("Enter the numbers n");
        for (i = 0; i < n; ++i)
            scanf("%d", &number[i]);
 
        for (i = 0; i < n; ++i) 
        {
 
            for (j = i + 1; j < n; ++j)
            {
 
                if (number[i] > number[j]) 
                {
 
                    a =  number[i];
                    number[i] = number[j];
                    number[j] = a;
 
                }
 
            }
 
        }
 
        printf("The numbers arranged in ascending order are given below n");
        for (i = 0; i < n; ++i)
            printf("%dn", number[i]);
 }

merge sort

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

function merge(list, start, midpoint, end) {
    const left = list.slice(start, midpoint);
    const right = list.slice(midpoint, end);
    for (let topLeft = 0, topRight = 0, i = start; i < end; i += 1) {
        if (topLeft >= left.length) {
            list[i] = right[topRight++];
        } else if (topRight >= right.length) {
            list[i] = left[topLeft++];
        } else if (left[topLeft] < right[topRight]) {
            list[i] = left[topLeft++];
        } else {
            list[i] = right[topRight++];
        }
    }
}

function mergesort(list, start = 0, end = undefined) {
    if (end === undefined) {
        end = list.length;
    }
    if (end - start > 1) {
        const midpoint = ((end + start) / 2) >> 0;
        mergesort(list, start, midpoint);
        mergesort(list, midpoint, end);
        merge(list, start, midpoint, end);
    }
    return list;
}

mergesort([4, 7, 2, 6, 4, 1, 8, 3]);