GATE Exam  >  GATE Questions  >  The degree sequence of a simple graph is the ... Start Learning for Free
The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?


  • a)
    I and II

  • b)
    III and IV

  • c)
    II and IV

  • d)
    IV only

Correct answer is option 'C'. Can you explain this answer?
Verified Answer
The degree sequence of a simple graph is the sequence of the degrees o...
Havel Hakimi theorem:

Arrange the degree of vertices in descending order

eg. d1, d2, d3... dn

Discard dand subtract '1' from the next 'di' degrees

Ex:3,2,2,1,1


discard degree 3 and subtract one from the next highest 3 degrees. It means removing a vertex of degree 3 that refers to removing 3 edges in the graphs.

So, 1,1,0,1


0,0,1,0  We should not get any negative value if it's negative, this is not a valid sequence, and Repeat it till we get the '0' sequence.


Option 1: 7, 6, 5, 4, 4, 3, 2, 1


5,4,3,3, 2, 1, 0

3, 2, 2, 1, 0, 0

1,1,0,0,0


0,0,0,0,0


Hence true.

Option 2:  6, 6, 6, 6, 3,3,2, 2

5, 5, 5, 2, 2, 1, 2 (put them in descending order)

5, 5, 5, 2, 2, 2, 1

3, 0, 0, 0, 1 (descending order)

3,1,0,0,0

0,-1,-1,0


Hence False.

Option 3: 7, 6, 6, 4, 4, 3, 2, 2

5,5, 3, 3, 2, 1, 1

4, 2, 2, 1, 0, 1

4, 2, 2, 1, 1, 0 (descending order)

1,1,0,0,0

Hence True.

Option 4: 8, 7, 7, 6, 4, 2, 1, 1

There is a degree 8 but there are only '8' vertices. A vertex cannot have an edge to itself in a simple graph. This is not a valid sequence.


Hence False.


The correct answer is II and IV.
View all questions of this test
Explore Courses for GATE exam

Similar GATE Doubts

The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer?
Question Description
The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer?.
Solutions for The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for GATE. Download more important topics, notes, lectures and mock test series for GATE Exam by signing up for free.
Here you can find the meaning of The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?a)I and IIb)III and IVc)II and IVd)IV onlyCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice GATE tests.
Explore Courses for GATE exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev