Arrays!

Given an array of size N that contains values between 1 and N-1, find the duplicate element(assuming there is only one)?.
Solution:
a) Count all the numbers in the array. call it ActualSumb) Find the sum of first N-1 natural numbers from 1 to N-1. The formula is N*(N+1)/2. Call it TotalSum.c) The answer is Actual Sum - Total Sum
Example:Array : {3, 4, 1, 3, 2}
Actual Sum: 13
Total Sum : 10 (Here, N =5, N-1 = 4, thus Total Sum =(5*4)/2 = 10)Result : 13 - 10 = 3
Time Complexity = 0(n)

If it contains values between 1 and N+1, how would you find the missing element (again assuming there is only one missing)?
Solution:

a) Count all the numbers in the array. call it ActualSum

b) Find the sum of first N+1 natural numbers from 1 to N+1. The formula is N*(N+1)/2. Call it TotalSum.

c) The answer is Total Sum - Actual Sum
Example:Array : {3, 6, 1, 5, 2}
Actual Sum: 17
Total Sum : 21 (Here, N+1 = 6, thus Total Sum =(7*6)/2 = 21)
Result : 21 - 17 = 4
Time Complexity = 0(n)

whats the buzz around programming?

When a solution is designed for a problem, is it just enough the problem is solved?.
Certainly NO!. Its all about designing the optimized solution.

What is Opimitizing the solution?. Usage of resoures such as time (CPU), memory in an efficient way.

How does a programmer develop a practice of developing an optimized solution?. Read thru this blog, you will get new ideas that you could make use in your projects.

Programming questions are always used to access a candiate in an interview!.. Read this blog to get those questions and help yourself achieve your goals!...

Simple... Its all bout data structures, design patterns, optimization!.

More to follow, keep watching this space!.