W3Schools Tryit Editor

Python

Java

def merge(left, right):
    result = []
    i = j = 0
    
    while i < len(left) and j < len(right):
        if left[i] < right[j]:
            result.append(left[i])
            i += 1
        else:
            result.append(right[j])
            j += 1
            
    result.extend(left[i:])
    result.extend(right[j:])
    
    return result

def mergeSort(arr):
    step = 1  # Starting with sub-arrays of length 1
    length = len(arr)
    
    while step < length:
        for i in range(0, length, 2 * step):
            left = arr[i:i + step]
            right = arr[i + step:i + 2 * step]
            
            merged = merge(left, right)
            
            # Place the merged array back into the original array
            for j, val in enumerate(merged):
                arr[i + j] = val
                
        step *= 2  # Double the sub-array length for the next iteration
        
    return arr

unsortedArr = [3, 7, 6, -10, 15, 23.5, 55, -13]
sortedArr = mergeSort(unsortedArr)
print("Sorted array:", sortedArr)

#Python

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

void merge(double left[], int leftSize, double right[], int rightSize, double result[]) {
    int i = 0, j = 0, k = 0;

while (i < leftSize && j < rightSize) {
        if (left[i] < right[j]) {
            result[k++] = left[i++];
        } else {
            result[k++] = right[j++];
        }
    }

while (i < leftSize) {
        result[k++] = left[i++];
    }

while (j < rightSize) {
        result[k++] = right[j++];
    }
}

void mergeSort(double arr[], int length) {
    int step = 1;

while (step < length) {
        for (int i = 0; i < length; i += 2 * step) {
            int leftSize = step;
            int rightSize = step;

if (i + step >= length) leftSize = length - i;
            if (i + step >= length) rightSize = 0;
            else if (i + 2 * step > length) rightSize = length - (i + step);

double *left = (double *)malloc(leftSize * sizeof(double));
            double *right = (double *)malloc(rightSize * sizeof(double));
            double *merged = (double *)malloc((leftSize + rightSize) * sizeof(double));

for (int j = 0; j < leftSize; ++j) {
                left[j] = arr[i + j];
            }

for (int j = 0; j < rightSize; ++j) {
                right[j] = arr[i + step + j];
            }

merge(left, leftSize, right, rightSize, merged);

for (int j = 0; j < leftSize + rightSize; ++j) {
                arr[i + j] = merged[j];
            }

free(left);
            free(right);
            free(merged);
        }

step *= 2;
    }
}

int main() {
    double arr[] = {3, 7, 6, -10, 15, 23.5, 55, -13};
    int length = sizeof(arr) / sizeof(arr[0]);

mergeSort(arr, length);

printf("Sorted array: ");
    for (int i = 0; i < length; ++i) {
        printf("%.1f ", arr[i]);
    }
    printf("\n");

return 0;
}

//C

import java.util.Arrays;

public class Main {
    public static double[] merge(double[] left, double[] right) {
        double[] result = new double[left.length + right.length];
        int i = 0, j = 0, k = 0;

while (i < left.length && j < right.length) {
            if (left[i] < right[j]) {
                result[k++] = left[i++];
            } else {
                result[k++] = right[j++];
            }
        }

while (i < left.length) {
            result[k++] = left[i++];
        }

while (j < right.length) {
            result[k++] = right[j++];
        }

return result;
    }

public static double[] mergeSort(double[] arr) {
        int step = 1;
        int length = arr.length;

while (step < length) {
            for (int i = 0; i < length; i += 2 * step) {
                int mid = Math.min(i + step, length);
                int end = Math.min(i + 2 * step, length);

double[] left = Arrays.copyOfRange(arr, i, mid);
                double[] right = Arrays.copyOfRange(arr, mid, end);

double[] merged = merge(left, right);

System.arraycopy(merged, 0, arr, i, merged.length);
            }
            step *= 2;
        }

return arr;
    }

public static void main(String[] args) {
        double[] unsortedArr = {3, 7, 6, -10, 15, 23.5, 55, -13};
        double[] sortedArr = mergeSort(unsortedArr);

System.out.println("Sorted array: " + Arrays.toString(sortedArr));
    }
}

//Java