Trainee Technology

Tip 1: You must remember the formulas of problems as much as you can. 
Tip 2: Clear your basics for solving aptitude questions. 
Tip 3: Give practice tests

Tip 1: Learn and remember the complexity of each sorting algorithm.
Tip 2: Give DSA Mcqs practice test at any online DSA site as I chose GFG

If you only have the knowledge of matrix rotation clockwise 90 degrees and you can easily solve this.
Note- Refer the 90degree clockwise rotation of matrix

Let main Matrix size of row and column be n=3. and start row index is 1, start column index is 1 of submatrix
i = start row index of submatrix , j = start column index of submatrix, n = n- size of submatrix

During first iteration – 
a[i][j] = Element at first index (leftmost corner top)= 1.
a[j][n-1-i]= Rightmost corner top Element = 3.
a[n-1-i][n-1-j] = Rightmost corner bottom element = 9.
a[n-1-j][i] = Leftmost corner bottom element = 7.
Move these elements in the clockwise direction. 
During second iteration – 
a[i][j] = 2.
a[j][n-1-i] = 6.
a[n-1-i][n-1-j] = 8.
a[n-1-j][i] = 4. 
Similarly, move these elements in the clockwise direction.

My Algorithm: 

initialize d=INTEGER.MAXLENGTH, i, j, sum1=0, p1, p2; 

for i=0 to 
sum1=0; 

for j=0 to 
sum1+=a1[i]+a2[j]; 

difference=sum1-sum ; 

if(difference
{d=difference; //update difference 

p1=a1[i];p2=a2[j]; //update pair value element 

}

Hint: I used the hashMap technique 

Algorithm: 

Step 1- char ar[] = str.split(“//”) /*split string by space and add into array */

Step 2- HashMap hp = new HashMap(); 

Step 3- for loop 0 to 
If hashmap does not contains a string (word) then enter that word into hashmap as key and put its value as 1;

else 

/*increase the value of a particular key which is already present in the hash map (increase the frequency if word again occurred in the array); */

Tip 1: Be calm, honest and Confident.
Tip 2: Well prepare your introduction.
Tip 3: Read somethings about the company for which you are giving the interview.