Skip to main content

Coding Interview Question: A Function sum(a)(b)(c)...( n)() Which Returns Sum of a+b+c...+n

Image result for coding interview question
Coding Interview Question:
Write a function sum(a)(b)(c)...( n)() , which returns the sum of a+b+c...+n

One line solutions (in Javascript):
1. If a,b,c...n are consecutive integers starting from 1 or 0 then the answer is:
const sum = a => a*(a+1)/2
We use Carl Friedrich Gauss method

2. If a,b,c...n are consecutive integers starting from any number then the answer is:
const sum = (a, b) => (b*(b+1)-(a-1)*a)/2
We use Carl Friedrich Gauss method

3. If a,b,c...n are non-consecutive any integers then the answer is:
const sum = a => b => b ? sum(a+b) : a
We use recursive here.

Watch the solutions in action here: https://repl.it/@VinitKhandelwal/sum-of-n-numbers

Comments

Post a Comment

Popular posts from this blog

Python - List - Append, Count, Extend, Index, Insert, Pop, Remove, Reverse, Sort

🐍 Advance List List is widely used and it's functionalities are heavily useful. Append Adds one element at the end of the list. Syntax list1.append(value) Input l1 = [1, 2, 3] l1.append(4) l1 Output [1, 2, 3, 4] append can be used to add any datatype in a list. It can even add list inside list. Caution: Append does not return anything. It just appends the list. Count .count(value) counts the number of occurrences of an element in the list. Syntax list1.count(value) Input l1 = [1, 2, 3, 4, 3] l1.count(3) Output 2 It returns 0 if the value is not found in the list. Extend .count(value) counts the number of occurrences of an element in the list. Syntax list1.extend(list) Input l1 = [1, 2, 3] l1.extend([4, 5]) Output [1, 2, 3, 4, 5] If we use append, entire list will be added to the first list like one element. Extend, i nstead of considering a list as one element, it joins the two lists one after other. Append works in the following way. Input l1 = [1, 2, 3] l1.append([4, 5]) Output...
Post a Comment
Read more

Difference between .exec() and .execPopulate() in Mongoose?

Here I answer what is the difference between .exec() and .execPopulate() in Mongoose? .exec() is used with a query while .execPopulate() is used with a document Syntax for .exec() is as follows: Model.query() . populate ( 'field' ) . exec () // returns promise . then ( function ( document ) { console . log ( document ); }); Syntax for .execPopulate() is as follows: fetchedDocument . populate ( 'field' ) . execPopulate () // returns promise . then ( function ( document ) { console . log ( document ); }); When working with individual document use .execPopulate(), for model query use .exec(). Both returns a promise. One can do without .exec() or .execPopulate() but then has to pass a callback in populate.
1 comment
Read more

Python Class to Calculate Distance and Slope of a Line with Coordinates as Input

🐍  Can be run on Jupyter Notebook #CLASS DESIGNED TO CREATE OBJECTS THAT TAKES COORDINATES AND CALCULATES DISTANCE AND SLOPE class Line:     def __init__(self,coor1,coor2):         self.coor1=coor1         self.coor2=coor2 #FUNCTION CALCULATES DISTANCE     def distance(self):         return ((self.coor2[0]-self.coor1[0])**2+(self.coor2[1]-self.coor1[1])**2)**0.5 #FUNCTION CALCULATES SLOPE         def slope(self):         return (self.coor2[1]-self.coor1[1])/(self.coor2[0]-self.coor1[0]) #DEFINING COORDINATES coordinate1 = (3,2) coordinate2 = (8,10) #CREATING OBJECT OF LINE CLASS li = Line(coordinate1,coordinate2) #CALLING DISTANCE FUNCTION li.distance() #CALLING SLOPE FUNCTION li.slope()
Post a Comment
Read more