ALGORITHM vs. FLOWCHART

Definition of Algorithm
To write a logical step-by-step method to solve the problem is called algorithm, in other words, an algorithm is a procedure for solving problems. In order to solve a mathematical or computer problem, this is the first step of the procedure. An algorithm includes calculations, reasoning and data processing. Algorithms can be presented by natural languages, pseudo code and flowcharts, etc.



Definition of Flowchart
A flowchart is the graphical or pictorial representation of an algorithm with the help of different symbols, shapes and arrows in order to demonstrate a process or a program. With algorithms, we can easily understand a program. The main purpose of a flowchart is to analyze different processes. Several standard graphics are applied in a flowchart:

 

Symbol	Purpose	Description
	Flow line	Indicates the flow of logic by connecting symbols.
	Terminal(Stop/Start)	Represents the start and the end of a flowchart.
	Input/Output	Used for input and output operation.
	Processing	Used for arithmetic operations and data-manipulations.
	Decision	Used for decision making between two or more alternatives.
	On-page Connector	Used to join different flowline
	Off-page Connector	Used to connect the flowchart portion on a different page.
	Predefined Process/Function	Represents a group of statements performing one processing task.

 

S.NO	ALGORITHM	FLOWCHART
1.	Algorithm is step by step procedure to solve the problem.	Flowchart is a diagram created by different shapes to show the flow of data.
2.	Algorithm is complex to understand.	Flowchart is easy to understand.
3.	In algorithm plain text are used.	In flowchart, symbols/shapes are used.
4.	Algorithm is easy to debug.	Flowchart it is hard to debug.
5.	Algorithm is difficult to construct.	Flowchart is simple to construct.
6.	Algorithm does not follow any rules.	Flowchart follows rules to be constructed.
7.	Example: Add two numbers entered by the user. ALGORITHM: A.     Begin         B.      Read value of variable 1 and variable 2. C.      Add the values of variable 1 and variable 2. D.     Assign the sum to Total variable. E.      Display the value of total. F.      End	Example: Add two numbers entered by the user. FLOWCHART:

 

Big Data Computing: Quiz Assignment-VIII Solutions (Week-8)

1. Which of the following are provided by spark API for graph parallel computations:
i. joinVertices
ii. subgraph
iii. aggregateMessages
A. Only (i)
B. Only (i) and (ii)
C. Only (ii) and (iii)
D. All of the mentioned
Answer: D) All of the mentioned

2. Which of the following statement(s) is/are true in the context of Apache Spark GraphX operators ?
S1: Property operators modify the vertex or edge properties using a user defined map function and produces a new graph.
S2: Structural operators operate on the structure of an input graph and produces a new graph. S3: Join operators add data to graphs and produces a new graphs.
A. Only S1 is true
B. Only S2 is true
C. Only S3 is true
D. All of the mentioned
Answer: D) All of the mentioned


3. True or False ?
The outerJoinVertices() operator joins the input RDD data with vertices and returns a new graph. The vertex properties are obtained by applying the user defined map() function to the all vertices, and includes ones that are not present in the input RDD.
A. True
B. False
Answer: A) True


4. Which of the following statements are true ?
S1: Apache Spark GraphX provides the following property operators - mapVertices(), mapEdges(), mapTriplets()
S2: The RDDs in Spark, depend on one or more other RDDs. The representation of dependencies in between RDDs is known as the lineage graph. Lineage graph information is used to compute each RDD on demand, so that whenever a part of persistent RDD is lost, the data that is lost can be recovered using the lineage graph information.
A. Only S1 is true
B. Only S2 is true
C. Both S1 and S2 are true
D. None of the mentioned
Answer: C) Both S1 and S2 are true


5. GraphX provides an API for expressing graph computation that can model the
abstraction.
A. GaAdt
B. Pregel
C. Spark Core
D. None of the mentioned
Answer: B) Pregel


6. Match the following:
A. Dataflow Systems i. Vertex Programs
B. Graph Systems ii. Parameter Servers
C. Shared Memory Systems iii. Guinea Pig
A. A:ii, B: i, C: iii
B. A:iii, B: i, C: ii
C. A:ii, B: iii, C: i
D. A:iii, B: ii, C: i
Answer: B) A:iii, B: i, C: ii


7. Which of the following statement(s) is/are true in context of Parameter Servers.
S1: A machine learning framework
S2: Distributes a model over multiple machines
S3: It offers two operations: (i) Pull for query parts of the model (ii) Push for update parts of the model.
A. Only S1 is true
B. Only S2 is true
C. Only S3 is true
D. All of the mentioned
Answer: D) All of the mentioned


8.

What is the PageRank score of vertex B after the second iteration? (Without damping factor)
Hint:- The basic PageRank formula is:

Where, PRt+1(u): page rank of node u under consideration PRt(v): previous page rank of node ‘v’ pointing to node ‘u’ C(v): outgoing degree of vertex ‘v’
A. 1/6
B. 1.5/12
C. 2.5/12
D. 1/3 

Answer: A) 1/6

Explanation: The Page Rank score of all vertex is calculated as follows: 

	Iteration0	Iteration1	Iteration2	Page Rank
A	1/4	1/12	1.5/12	1
B	1/4	2.5/12	2/12	2
C	1/4	4.5/12	4.5/12	4
D	1/4	4/12	4/12	3