daa-lab/mergeSort.java

import java.util.*;
public class mergeSort{
    static void merge(int arr[], int left, int mid, int right, int temp[]){
        int i = left;
        int j = mid+1;
        int k = left;

        while(i<=mid && j<=right){
            if(arr[i]<=arr[j]){
                temp[k++] = arr[i++];
            }else{
                temp[k++] = arr[j++];
            }
        }
        while(i<=mid)
            temp[k++] = arr[i++];
        while(j<=right)
            temp[k++] = arr[j++];

        for(int x = left;x<=right;x++){
            arr[x] = temp[x];
        }
    }
    static void mergeSort(int arr[], int left, int right, int temp[]){
        if(left<right){
            int mid = (right+left)/2;
            mergeSort(arr, left, mid, temp);
            mergeSort(arr, mid+1, right, temp);
            merge(arr, left, mid, right, temp);
        }
    }

    public static void main(String[] args){
        Scanner sc =  new Scanner(System.in);

        System.out.print("Enter number of elements: ");
        int n= sc.nextInt();

        int arr[] = new int[n];
        int temp[] = new int[n];

        System.out.println("Enter "+n+" elements: ");
        for(int i =0;i<n;i++){
            arr[i] = sc.nextInt();
        }
        mergeSort(arr,0,n-1,temp);
        System.out.println("\nSorted array:");
        for(int i =0;i<n;i++){
            System.out.print(arr[i]+ " ");
        }
        sc.close();
    }
}