In this article I am going to explain how to compare two excel
sheets data and highlight the missing data. This article is helpful in BPO
industry those who are dealt with finance and insurance sector.

Now a day’s everything automated in this comparison of two excel
sheets is taking too lengthy process and our eyes also gets strained so to
avoid that read the article and practice yourself with a sample data. If you
have any questions let me know.

Here I am using two functions 

VLOOKUP()

       MATCH()

Usage of VLOOKUP() function in excel:

Syntax of Vlookup function: 

First go to formulas tab and select Lookup & Reference
then click on VLOOKUP():

 Based on the syntax of the function pass the values like below:

Lookup Value - > What is the required value for searching.

Table Array -> Select the range where you want to find the given element.

Column Index -> Column number 

Range Lookup -> True or False

See the below practice excel sheet which contains the data:

 

By Using MATCH() Function:

Match Function Syntax:

 

 Go to formulas tab and select Lookup & Reference
then click on MATCH().

Fill the formula columns like below:

Look up value -> What the element you want to search, select that column.

Look up array -> Where you want to search the element select the range.

Match Type -> It is 0,1,-1  0 for exact match 1 or -1 greater than or less than

See the below practice excel sheet which contains the data:

 

PLEASE NOTE : in the above practice sheet NA means no match found.

Merge Sort is a sorting technique based on divide and conquer
technique with comparison. 

Conceptually, a merge sort works as follows :

i) Divide the unsorted list into n sublists, each containing 1 element (a list
of 1 element is considered sorted).

ii) Repeatedly merge sublists to produce new sublists until there is only 1
sublist remaining. This will be the sorted list.

Merge sort - Visualization

 

Worst Case performance: O (n log n)

Best case Performance: O (n log n) for typical O(n) natural
variant

Average performance:  O(n log n)

Worst case space complexity : O(n) 

Merge Sort

Merge Sort Pseudocode and Algorithm:

MergeSort
(Array(First..Last))

Begin

If Array contains only one element Then

     Return Array

Else

     Middle= ((Last + First)/2) rounded
down to the nearest integer

     LeftHalfArray =
MergeSort(Array(First..Middle))

     RightHalfArray =
MergeSort(Array(Middle+1..Last))

     ResultArray = Merge(LeftHalfArray,
RightHalfArray)

     Return ResultArray

EndIf

End MergeSort

Java Program for Merge Sort:

import java.util.Scanner;

public class MergeSort

{

    public static void sort(int[] a, int low, int high)

    {

        int N = high - low;

        if (N <= 1)

            return;

        int mid = low + N / 2;

        sort(a, low, mid);

        sort(a, mid, high);

        int[] temp = new int[N];

        int i = low, j = mid;

        for (int k = 0; k < N; k++)

        {

            if (i == mid)

                temp[k] = a[j++];

            else if (j == high)

                temp[k] = a[i++];

            else if (a[j] < a[i])

                temp[k] = a[j++];

            else

                temp[k] = a[i++];

        }

        for (int k = 0; k < N; k++)

            a[low + k] = temp[k];

    }

    public static void main(String[] args)

    {

        Scanner scan = new Scanner(System.in);

        System.out.println("Merge Sort Test\n");

        int n, i;
        System.out.println("Enter number of integer elements");

        n = scan.nextInt();
        int arr[] = new int[n];
        System.out.println("\nEnter " + n + " integer elements");

        for (i = 0; i < n; i++)

            arr[i] = scan.nextInt();

        sort(arr, 0, n);
        System.out.println("\nElements after sorting ");

        for (i = 0; i < n; i++)

            System.out.print(arr[i] + " ");

        System.out.println();

    }

} 

Output :