TECHCSE.COM -- BLOG: 2012

Wednesday, 28 November 2012

First and Follow Sets

First and Follow Sets

Rules for First Sets

If X is a terminal then First(X) is just X!
If there is a Production X → ε then add ε to first(X)
If there is a Production X → Y1Y2..Yk then add first(Y1Y2..Yk) to first(X)
First(Y1Y2..Yk) is either

First(Y1) (if First(Y1) doesn't contain ε)
OR (if First(Y1) does contain ε) then First (Y1Y2..Yk) is everything in First(Y1) <except for ε > as well as everything in First(Y2..Yk)
If First(Y1) First(Y2)..First(Yk) all contain ε then add ε to First(Y1Y2..Yk) as well.

Rules for Follow Sets

First put $ (the end of input marker) in Follow(S) (S is the start symbol)
If there is a production A → aBb, (where a can be a whole string) then everything in FIRST(b) except for ε is placed in FOLLOW(B).
If there is a production A → aB, then everything in FOLLOW(A) is in FOLLOW(B)
If there is a production A → aBb, where FIRST(b) contains ε, then everything in FOLLOW(A) is in FOLLOW(B)

Here an example for you to follow through.

The Grammar

E → TE'

E' → +TE'

E' → ε

T → FT'

T' → *FT'

T' → ε

F → (E)

F → id

First Sets

Follow Sets

We Want to make First sets so first we list the sets we need

FIRST(E) = {}

FIRST(E') = {}

FIRST(T) = {}

FIRST(T') = {}

FIRST(F) = {}

First We apply rule 2 to T' → ε and E' → ε

FIRST(E) = {}

FIRST(E') = {ε}

FIRST(T) = {}

FIRST(T') = {ε}

FIRST(F) = {}

First We apply rule 3 to T' → *FT' this rule tells us that we can add everything in First(*FT') into First(T')

Since First(*) useing rule 1 is * we can add * to First(T')

FIRST(E) = {}

FIRST(E') = {+,ε}

FIRST(T) = {}

FIRST(T') = {*,ε}

FIRST(F) = {}

First We apply rule 3 to T' → *FT' this rule tells us that we can add everything in First(*FT') into First(T')

Since First(*) useing rule 1 is * we can add * to First(T')

FIRST(E) = {}

FIRST(E') = {+,ε}

FIRST(T) = {}

FIRST(T') = {*,ε}

FIRST(F) = {}

Two more productions begin with terminals F → (E) and F → id If we apply rule 3 to these we get...

FIRST(E) = {}

FIRST(E') = {+,ε}

FIRST(T) = {}

FIRST(T') = {*,ε}

FIRST(F) = {'(',id}

Next we apply rule 3 to T → FT' once again this tells us that we can add First(FT') to First(T)

Since First(F) doesn't contain ε that means that First(FT') is just First(F)

FIRST(E) = {}

FIRST(E') = {+,ε}

FIRST(T) = {'(',id}

FIRST(T') = {*,ε}

FIRST(F) = {'(',id}

Lastly we apply rule 3 to E → TE' once again this tells us that we can add First(TE') to First(E)

Since First(T) doesn't contain ε that means that First(TE') is just First(T)

FIRST(E) = {'(',id}

FIRST(E') = {+,ε}

FIRST(T) = {'(',id}

FIRST(T') = {*,ε}

FIRST(F) = {'(',id}

Doing anything else doesn't change the sets so we are done!

We want to make Follow sets so first we list the sets we need

FOLLOW(E) = {}

FOLLOW(E') = {}

FOLLOW(T) ={}

FOLLOW(T') = {}

FOLLOW(F) = {}

The First thing we do is Add $ to the start Symbol 'E'

FOLLOW(E) = {$}

FOLLOW(E') = {}

FOLLOW(T) ={}

FOLLOW(T') = {}

FOLLOW(F) = {}

Next we apply rule 2 to E' →+TE' This says that everything in First(E') except forε should be in Follow(T)

FOLLOW(E) = {$}

FOLLOW(E') = {}

FOLLOW(T) ={+}

FOLLOW(T') = {}

FOLLOW(F) = {}

Next we apply rule 3 to E →TE' This says that we should add everything in Follow(E) into Follow(E')

FOLLOW(E) = {$}

FOLLOW(E') = {$}

FOLLOW(T) ={+}

FOLLOW(T') = {}

FOLLOW(F) = {}

Next we apply rule 3 to T → FT' This says that we should add everything in Follow(T) into Follow(T')

FOLLOW(E) = {$}

FOLLOW(E') = {$}

FOLLOW(T) ={+}

FOLLOW(T') = {+}

FOLLOW(F) = {}

Now we apply rule 2 to T' →*FT' This says that everything in First(T') except for ε should be in Follow(F)

FOLLOW(E) = {$}

FOLLOW(E') = {$}

FOLLOW(T) ={+}

FOLLOW(T') = {+}

FOLLOW(F) = {*}

Now we apply rule 2 to F → (E) This says that everything in First(')') should be in Follow(E)

FOLLOW(E) = {$,)}

FOLLOW(E') = {$}

FOLLOW(T) ={+}

FOLLOW(T') = {+}

FOLLOW(F) = {*}

Next we apply rule 3 to E → TE' This says that we should add everything in Follow(E) into Follow(E')

FOLLOW(E) = {$,)}

FOLLOW(E') = {$,)}

FOLLOW(T) = {+}

FOLLOW(T') = {+}

FOLLOW(F) = {*}

Next we apply rule 4 to E' → +TE' This says that we should add everything in Follow(E') into Follow(T) (because First(E') contains ε)

FOLLOW(E) = {$,)}

FOLLOW(E') = {$,)}

FOLLOW(T) = {+,$,)}

FOLLOW(T') = {+}

FOLLOW(F) = {*}

Next we apply rule 3 to T → FT' This says that we should add everything in Follow(T) into Follow(T')

FOLLOW(E) = {$,)}

FOLLOW(E') = {$,)}

FOLLOW(T) = {+,$,)}

FOLLOW(T') = {+,$,)}

FOLLOW(F) = {*}

Finaly we apply rule 4 to T' → *FT' This says that we should add everything in Follow(T') into Follow(F)

FOLLOW(E) = {$,)}

FOLLOW(E') = {$,)}

FOLLOW(T) = {+,$,)}

FOLLOW(T') = {+,$,)}

FOLLOW(F) = {*,+,$,)}

Thanks to James Brunskill for this sharing.

Saturday, 20 October 2012

Tech Mahindra Placement Paper -- Set 10

Tech Mahindra Placement Paper -- Set 10:

1. What is Call Money ?
(A) Money borrowed or lent for a day or over night
(B) Money borrowed for more than one day but upto 3 days
(C) Money borrowed for more than one day but upto 7 days
(D) Money borrowed for more than one day but upto 14 days
(E) None of these

2. Which of the following statements(s) is/are True about the exports of China which is a close competitor of India ?
(i) China’s economic success is basically on the fact that it exports cheaper goods to rich
nations like the USA, etc.
(ii) In the year 2007 China’s exports became almost 40% of its GDP.
(iii) When compared to India China’s share in the World Exports is more than 30%
whereas India’s share is mere 6% of the global exports.
(A) Only (i)
(B) Only (ii)
(C) Both (i) and (ii)
(D) All (i), (ii) and (iii)
(E) None of these

Tech Mahindra Placement Paper -- Set --9:

1. Which of the following statement(s) is(are) not true
a. Literate workers have small families than illiterate workers.
b. Families with 2 or less than 2 children are commoner than families with 3 or more children.
c. 2 children families constitute 60% of the families of workers.
d. More the no. of children a worker has the more illiterate he is.
e. None the above statement is true.
Ans: e

2. ......of a mutual instrument vibrate 6,8 & 12 intervals respectively. If all three vibrate together what is the time interval before all vibrate together again?
LCM of NR
Ans: 1/2 sec

3. Certain no. of men can finish a piece of work in 10 days. If however there were 10 men less it will take 10 days more for the work to be finished. How many men were there originally.
Ans: 110 men

Tech Mahindra Placement Paper -- Set 8

Tech Mahindra Placement Paper -- Set 8:

Q.1 If Thursday was the day after the day before yesterday five days ago, what is the least number of days ago when Sunday was three days before the day after tomorrow?

Two days ago

Three days ago

Four days ago

Five days ago

None of these

Q.2 A train started from station 'A' and proceeded towards station 'B' at a speed of 48 Km/hr. Forty-five minutes later another train started from station 'B' and proceeded towards station 'A' at 50 Km/hr. If the distance between the two stations is 232 Km, at what distance from station 'A' will the trains meet?

132 Km

144 Km

108 Km

160 Km

None of these

Tech Mahindra Placement Paper -- Set 7

Tech Mahindra Placement Paper -- Set 7:

Instruction for Q. Nos. 1 to 4 :

From the two options given below each sentence select the one to fill the blank appropriately.

Q.1 Please fill up this _______ and give it back to me.

form

farm

Q.2 He is not one to _________ defeat easily.

except

Q.3 Are you ________ that he has been lying to me.

inferring

implying

Q.4 He is an ________ personality.

imminent

eminent

Tech Mahindra Technical Aptitude Questions:-

1. Another Problem with

# define TRUE 0

some code

while(TRUE)

{

some code

}

This won't go into the loop as TRUE is defined as 0

2. The following variable is available in file1.c

static int average_float;

all the functions in the file1.c can access the variable

3. A question in structures where the members are dd,mm,yy.

mm:dd:yy

09:07:9

Tech Mahindra Placement Paper Set - 6:-

This section consists of 29 problems. The questions are simple though time consuming.
1. If a boat is moving in upstream with velocity of 14 km/hr and goes downstream with a velocity of 40
km/hr, then what is the speed of the stream ?
(a) 13 km/hr
(b) 26 km/hr
(c) 34 km/hr
(d) none of these
Ans: A

2. Find the value of ( 0.75 * 0.75 * 0.75 - 0.001 ) / ( 0.75 * 0.75 - 0.075 + 0.01)
(a) 0.845
(b) 1.908
(c) 2.312
(d) 0.001
Ans: A

Tech Mahindra Placement Paper -- Set 5:

2. ......of a mutual instrument vibrate 6,8 & 12 intervals
respectively. If all three vibrate together what is the time
interval before all vibrate together again?
LCM of NR
Ans: 1/2 sec

TECH MAHINDRA PLACEMENT PAPER -- Set 4:

“Find the range of real values of x satisfying the inequalities 4x - 5 > 7 and 5x - 14 > 16" a) x > 3 b) x > 6 c) x < 3 d) x < 6
Answer : b) x> 6
Solution :
4x - 5 > 7 => 4x > 12 => x > 3 ...(1)
and 5x - 14 > 16 => 5x >30 => x > 6 ...(2)
Since 6 is greater than 3, for both inequalities namely (1) and (2) to be satisfied, x should be greater than 6 or x > 6.

Krishnakumar, Raghunandan, Chinnan and Aibak had an interesting discussion on the following:
“Find the range of real values of x not satisfying even one of the inequalities 6x - 8 > 40 and 9x - 19 > 80"
a) x greater than 8 b) x lesser than or equal to 8 c) x lesser to 8 d) x greater than or equal to 8

Tech Mahindra Placement Paper 2011 -- Set 3:-

1. Find the output for the following C program

i=20,k=0;
for(j=1;j<i;j=1+4.(i/j))
{k+=j<10?4:3;
}
printf("%d", k);

Ans. k=4

2. Find the output for the following C program

int i =10
main()
{int i =20,n;
for(n=0;n<=i;)
{int i=10;
i++;
}
printf("%d", i);

Ans. i=20

Tech Mahindra Placement Paper -- Set 2:-

1. A man starts walking at 3 pm . ha walks at a speed of 4 km/hr on level ground and at a speed of 3 km/hr on uphill , 6 km/hr downhill and then 4 km/hr on level ground to reach home at 9 pm. What is the distance covered on one way?

Ans: 12 km

2. A grandma has many sons; each son has as many sons as his brothers. What is her age if it?s the product of the no: of her sons and grandsons plus no: of her sons?(age b/w 70 and 100).

Ans: 81

Tech Mahindra Placement Papers 2011 -- Set1 :-

1. There are total 15 people. 7 speaks french and 8 speaks spanish. 3 do not speak any language. Which part of total people speaks both languages.

Ans: 1/5

2. A jogger wants to save ?th of his jogging time. He should increase his speed by how much %age.

Ans: 33.33 %

3. A is an integer. Dividing 89 & 125 gives remainders 4 & 6 respectively. Find a ?

Ans: 17

CAPGEMINI PLACEMENT PAPER --SET 1

CAPGEMINI PLACEMENT PAPER --SET 1:

1. The average salary of 3 workers is 95 Rs. per week. If one earns Rs.115 and second earns Rs.65 how much is the salary of the 3rd worker.
Ans.105.

2. A 16 stored building has 12000 sq.feet on each floor. Company A rents 7 floors and company B rents 4 floors. What is the number of sq.feet of unrented floor space.
Ans.60000

3.During a given week A programmer spends 1/4 of his time preparing flow chart, 3/8 of his time coding and the rest of the time in debugging the programs. If he works 48 hours during the week , how many hours did he spend debugging the program.
Ans. 18.

Ericsson Placement Paper -- SET 1

Aptitude test: (75 mins)

1. A shop stores x kg of rice. The first customer buys half this amount plus half a kg of rice. The second customer buys half the remaining amount plus half a kg of rice. Then the third customer also buys half the remaining amount plus half a kg of rice. Thereafter, no rice is left in the shop. Which of the following best describes the value of x?
(1) 2 ≤ x ≤ 6
(2) 5 ≤ x ≤ 8
(3) 9 ≤ x ≤ 12
(4) 11≤ x ≤ 14
(5) 13 ≤ x ≤ 18

TCS Placement Paper: IET

TCS Placement Paper: IET,Lucknow

Question 1:

George can do a work in 60 days. George and Paul can do the same work in 20 days.How much time will Paul take to complete the same work if works alone?

Answer: 30days

Question 2:

Two people A and B starts running at 10:00 AM towards north at a speed of 40Kmph and 60Kmph respectively. After 2 hours(12:00 noon ), A turned left and B turned right. They stopped at 2:00 PM.Find the distance between A and B at 2:00 PM.

ITC INFOTECH PLACEMENT PAPER -- SET 5

ITC INFOTECH PLACEMENT PAPER -- SET 5:

APTITUDE:
All questions were of cat pattern.......and little bit time consuming and tricky these are .............

1) The length, width and height of a room is 3,2,1 respectively. The length of the room is doubled and height and width is halved .then percentage decrease in area of wall. is...........
a) 13.6%
b) 27.2%
c) 10%
d) none of these

2) A father purchases dress for his three daughter. The dresses are of same color but of different size .the dress is kept in dark room .What is the probability that all the three will not choose their own dress...
a) 2/3
b) 1/3
c) 1/6
d) 1/9

ITC Infotech Placement -- Set 4:

Welcome to ITC Infotech Placement Paper 2010. Here you will find ITC Infotech Placement Paper Pattern and Download questions of ITC Infotech Placement Paper 2010 with Answers & Solutions.

1. The length, width and height of a room is 3,2,1 respectively. The length of the room is doubled and height and width is halved .then percentage decrease in area of wall. is...........
a) 13.6% b) 27.2% c) 10% d) none of these

ITC Model Technical Interview Questions:

Note : These questions are frequently asked in Itc Infotech. This questions is not enough for Technical Interviews. so please prepare all of them in your Study Materials and this Questions also.

Define Strings?
what are the different types of access modifiers?
What is Recursion Function?

ITC Candidate Experience and Technical Questions

ITC Candidate Experience and Technical Questions:

Contributed by : Mahesh Pujari, B.M.S College of Engineering

Hi this is Mahesh Pujari (E&C) from BMSCE BANGALORE. We had ITC Infotech in our campus on 18th August. I am very lucky to be a member of ITC... after getting failed in many companies.
package is 3.05 lks per annum.

ITC INFOTECH is really a good company. Its a good consultancy company. The growth is good. Also we have a lot of onsite opportunities.

ITC infotech Placement paper 2012

ITC infotech Placement paper 2012 --Set 3:

Questions 1 - 4
At a formal dinner for eight; the host & hostesses are seated at opposite ends of a rectangular table. with three persons along each side. Each man must be seated next to at least one Woman and vice-versa. Allan is opposite to Dinne, who is not the hostess George has' a woman on his right and is opposite a woman Helga is at the hostess's right, next to Frank One person is seated between Belinda & Carol.
Q 1 Eric is the eighth person present. Eric must be :
I. the host II. seated to. Diane's right III. seated opposite Carol
A) I onIy B) III only C) I & II only D) I, II, III

Q 2 If each person is placed directly opposite his or her spouse, which of the following pairs must be married?
A. George & Helga
B. Belinda & Frank
C. Carol & Frank
D. George & Belinda
E. Eric & Helga

Q 3 Which person cannot be seated next to a person of the same sex?
A. Allan B. Belinda C. Carol D. Diane E. Eric

ITC INFOTECH PLACEMENT PAPER

ITC INFOTECH PLACEMENT PAPER --SET 2:

SECTION – I :: VERBAL ABILITY

Instructions for the section:
. The total time limit for the section is 15 minutes
. At the end of the time, please change to section III and DO NOT return to this section
. There is only one correct answer, tick mark the answer on the answer sheet in the correct box.
. There is no negative marking in the test
Directions: Each sentence below has one or two blanks, each blank indicating that something has been omitted. Beneath the sentence are five lettered words or sets of words. Choose the word or set of words for each blank that best fits the meaning of the sentence as a whole.

Q.1 While ________________ in his own approach of philosophy, the scholar was illogically,___________ his colleagues who averred that a seeker of knowledge must be free to select such doctrines as pleased him in every school.
A. indiscriminate……supportive of
B. electic……intolerant of
C. speculative….cordial to
D. problematical….dismissive of
E. theoretic…Impatient with

ITC INFOTECH QUESTION PAPER

ITC INFOTECH QUESTION PAPER -- SET 1:

1. The length, width and height of a room is 3,2,1 respectively. The length of the room is doubled and height and width is halved .then percentage decrease in area of wall. is...........

a) 13.6%                b) 27.2%            c) 10%                  d) none of these

2. A father purchases dress for his three daughter. The dresses are of same color   but of different size .the dress is kept in dark room .What is the probability that all the three will not choose their own dress...

a) 2/3                   b) 1/3                          c) 1/6                         d) 1/9

TCS New Pattern 2013

TCS New Pattern 2013:

An empty tankbe filled with aninlet pipe 'A' in 42 minutes. after 12 minutes an outlet pipe 'B' is opened which can empty the tank in 30 minutes.

TCS OPen Sesame Questions with solutions 2013

TCS OPen Sesame Questions with solutions

2013:

1. If 3y+x>2 & x+2y<=3, what can be said about the value of y?

-1 >-1 <-1 1

TCS New Pattern 2013 heritage

TCS New Pattern 2013, Heritage:
1. [Q-6]Jain housing complex on OMR has a democratically elected
governing council comprising of the president, secretary and the
treasurer. During their annual meeting,

TCS New Question PAttern 2013 - Solution

Solve for TCS New Question PAttern 2013:
Everyone is suggested to go through this. If anything found wrong please let us know through comment.
or in TechCSE facebook page:
1.
Rate at which A fill is 1/42 per min
A filled for 12 min so tank filled by A will be 12/42
Similarly B empty the tank for 6 min

TCS NEW PATTERN QUESTIONS 2013

TCS NEW PATTERN QUESTIONS 2013:

1. A boy wants to make cuboids of dimension 5m,6m & 7m from small cubes of .03m^3.Later he realized that he can make some cuboids by making it hollow.Then it takes some cubes less.What is the number of cubes to be removed

TCS Placement Aptitude Type 2013

TCS MOCK TEST PAPERS 2013

INTRODUCTION

Preparing for your campus placements could be one of the biggest challenges of college life. And being the culmination of all these years of study and effort, it can be quite stressful as well. Understanding the need of the hour, we have put together 5 Mock Test Papers for you to work out, verify and strategize.

Pages

Wednesday, 28 November 2012

Saturday, 20 October 2012

Tech Mahindra Placement Paper -- Set --9:

Tech Mahindra Technical Aptitude Questions:-

Tech Mahindra Placement Paper Set - 6:-

Tech Mahindra Placement Paper -- Set 5:

TECH MAHINDRA PLACEMENT PAPER -- Set 4:

Tech Mahindra Placement Paper 2011 -- Set 3:-

Tech Mahindra Placement Paper -- Set 2:-

Tech Mahindra Placement Papers 2011 -- Set1 :-

Friday, 19 October 2012

CAPGEMINI PLACEMENT PAPER --SET 1:

Ericsson Placement Paper -- SET 1

Tuesday, 16 October 2012

TCS Placement Paper: IET,Lucknow

Sunday, 14 October 2012

ITC Infotech Placement -- Set 4:

ITC Model Technical Interview Questions:

Saturday, 29 September 2012

Saturday, 8 September 2012

TCS MOCK TEST PAPERS 2013

INTRODUCTION