Find an Element in 2 dimensional sorted array

Objective : Write an algorithm to find an Element in 2 dimensional array where rows and columns are sorted respectively.

Input: A two dimensional sorted array, arrA[][].

Sorted 2D array

 

Output : True or false based on whether element exists and its location

Approach:

Read more

Find Whether Given String is palindrome or Not.

Objective : Write an algorithm to find Whether Given String is palindrome or Not.

Input:  A String,

Output: true or false on whether string is palindrome or not

Approach:

  • Use recursive approach
  • Compare first and last characters if they are not same- return false
  • If they are same make, remove the first and last characters and make a recursive call. 

Example:

Jain niaJ => compare ‘J’ with ‘J’ =>returns true

ain nia => compare ‘a’ with ‘a’ =>returns true

in ni => compare ‘i’ with ‘i’ =>returns true

n n => compare ‘n’ with ‘n’ =>returns true

string length <2 => returns true

Read more

Find two Missing Numbers in a Sequence of Consecutive Numbers

Objective : Write an algorithm to find two Missing Numbers in a Sequence of Consecutive Numbers

Input:  Array, arrA[] with two missing numbers and Range

Output : Two missing numbers

Approach:

    • Approach is very simple, Add all the given numbers say S
    • Calculate sum of N numbers by formula n(n+1)/2 , say N
    • Find sum of two missing numbers a+b = N-S

Read more

Find a Missing Number From a Sequence of Consecutive Numbers

Objective : You have been asked to Write an algorithm Find a Missing Number From a Sequence of Consecutive Numbers

Input:  Array, arrA[] with a missing number and Range

Output : missing number

Approach:

  • Approach is very simple, Add all the given numbers say S
  • Calculate sum of N numbers by formula n(n+1)/2 , say N
  • Find missing number m = N-S

Read more