Quiz 43: Find TAG and attributes of HTML code

Problem:

Given a  HTML line, find the tag and its attributes.
ex Name:<input type="text">, here tag is 'input' and attribute is 'type'

Input Format: 

included in code

$n='<a href="http://www.google.com" name="test" id="id1">Click me</a>';

Output Format: 
Attributes for tag a are href & name & id

Constraints: 
none

Sample Input

<a href="http://www.google.com" name="test" id="id1">Click me</a>

Sample Output:
Attributes for tag a are href & name & id

Explanations:
tag is a and others are attributes

---

Solution:

$n='<a href="http://www.google.com" name="test" id="id1">Click me</a>';
($a)=$n=~/<(.*?)\s/;
(@arr)=$n=~/\s(.*?)=/g;
print "attributes of tag $a are ";
$c=0;
foreach(@arr)
{
if($c>0){print "& "};
print "$_ ";
$c++;
}

---

Tips:

Tag is anything between < and space. attribute is anything between space and =

Quiz 42: Valid PAN card number verification

Problem:

Given a PAN card number, find whether number is valid or not.
Rule: Should follow format (UC)(UC)(UC)(UC)(UC)(D)(D)(D)(D)(UC)
where UC is upper case alphabet and D is digit

Input Format: 

n = no. of test cases
followed by n pancard numbers in different lines

Output Format: 
print "YES" for valid and "NO" for invalid

Constraints: 
none

Sample Input

3
ABCDE1234F
ABCDe1234F
ABCDE12345

Sample Output:
YES
NO
NO

Explanations:
for case 2, it contains lower case alphabet, so number is invalid

---

Solution:

chomp($n=<STDIN>);
for($i=0;$i<$n;$i++)
{
chomp($s=<STDIN>);
if($s =~ /[A-Z][A-Z][A-Z][A-Z][A-Z]\d\d\d\d[A-Z]/)
{
push(@out,"YES");
}
else
{
push(@out,"NO");
}
}
foreach(@out)
{
print "$_\n";
}

---

Tips:

[A-Z] means any upper case alphabet

Quiz 41: Find whether a phone number is valid or not

Problem:

Given a phone number, find whether number is valid or not.
Rule1: number should have 10 digits
Rule2: only numbers allowed

Input Format: 

n = no. of test cases
followed by n numbers in different lines

Output Format: 
print corresponding error for each line. print "Valid number" for valid number

Constraints: 
none

Sample Input

3
9876543210
999999999
9876543w21

Sample Output:
valid phone number
Phone number should have length 10
Phone number should have numbers only

Explanations:
for case 2, length is 9, so number is invalid

---

Solution:

chomp($n=<STDIN>);
for($i=0;$i<$n;$i++)
{
chomp($s=<STDIN>);
@arr=split(//,$s);
$l=@arr;
$c=0;
if($l != 10)
{
push(@out,"Phone number should have length 10");
$c++;
}
foreach(@arr){
if($_ !~ /\d/)
{
push(@out,"Phone number should have numbers only");
$c++;
last;
}}
if($c == 0)
{
push(@out,"valid phone number");
}
}
foreach(@out)
{
print "$_\n";
}

---

Tips:

\d is used to match digits only. [0-9] can also be used.

Quiz 40: Find matching regex at 1st and last psoition

Problem:

Given a 1 line sentence, find the term "india" and display result as following
print 1 if sentence starts with "india"
print 2 if sentence ends with "india"
print 0 if sentence starts and ends with "india"
else print -1

Input Format: 

n = no. of test cases
followed by n sentences in different lines

Output Format: 
print corresponding number for each line

Constraints: 
none

Sample Input

4
i live in india
india is the best
india is india
in india people are good

Sample Output:
2
1
0
-1

Explanations:
for 1st case, sentence ends with 'india', so print 2

---

Solution:

chomp($n=<STDIN>);
for($i=0;$i<$n;$i++)
{
chomp($s=<STDIN>);
@arr=split(/ /,$s);
$l=@arr;
if($arr[$l-1] =~ /india/ and $arr[0] =~ /india/)
{
push(@out,0);
}
elsif($arr[0] =~ /india/)
{
push(@out,1);
}
elsif($arr[$l-1] =~ /india/)
{
push(@out,2);
}
else
{
push(@out,-1)
}
}
foreach(@out)
{
print "$_\n";
}

---

Tips:

=~  /expression/ is used to match regex

Quiz 39: Find index of flowers

Problem:

Mohit wants to buy 2 flowers for pooja. He have m rupees and flower shop have n different flowers. Given price of each flower, find the indexes of 2 flowers such that all the money Mohit have is used.

Input Format: 

m = money
n = number of different flowers

cost of n flowers separated by space.

Output Format: 
index1 index2

Constraints: 
none

Sample Input

200
10
1 5 15 25 198 14 200 2 100 150

Sample Output:
5 8

Explanations:
198+2=200, index of 198 is 5 and index of 2 is 8

---

Solution:

chomp($m=<STDIN>);
chomp($n=<STDIN>);
chomp($l=<STDIN>);
@list=split(/ /,$l);
for($j=0;$j<$n;$j++)
{
for($k=$j+1;$k<$n;$k++)
{
if($m == $list[$j]+$list[$k])
{
print $j+1;
print " ";
print $k+1;
last;
}
}
}

---

Tips:

Use last to end the loop as soon as your job is done

Quiz 38: Find the minimum price of a product

Problem:

Given price offered for a product by N different companies. Find the minimum price and name of company

Input Format: 

n = no of offers

followed by n lines in format "price company name" ie separated by space.

Output Format: 
Minimum price is __ by ___

Constraints: 
none

Sample Input

5
17000 snapdeal
21000 amazon
16322 ebay
16321 flipkart
32000 homeshop18

Sample Output:
Minimum cost is 16321 by flipkart

Explanations:
Claerly minimum cost is 16321

---

Solution:

chomp($n=<STDIN>);
@data=();
for($i=0;$i<$n;$i++)
{
chomp($inp=<STDIN>);
@arr=split(" ",$inp);
push(@data,$arr[0]);
push(@data,$arr[1]);
}
%hash=@data;
@names = keys %hash;
@names = sort{$a<=>$b}@names;
$min = $names[0];
print "Minimum cost is $min by ";
print "$hash{$min}";

---

Tips:

Using HASH is best approach for such problems

Quiz 37:Find LCM of multiple numbers

Problem:

Take N numbers as input and print their LCM

Input Format: 

num1 num2 num3......ie numbers seperated by space

Output Format: 
LCM

Constraints: 
none

Sample Input

20 30 40 50

Sample Output:
LCM is 600

Explanations:
600 is LCM of 20.30.40.50

---

Solution:

sub gcf {
  my ($x, $y) = @_;
  ($x, $y) = ($y, $x % $y) while $y;
  return $x;
}

sub lcm {
  return($_[0] * $_[1] / gcf($_[0], $_[1]));
}

sub multilcm {
       my $x = shift;
       $x = lcm($x, shift) while @_;
       return $x;
    }

chomp($num=<STDIN>);
@arr=split(" ",$num);
$ans=multilcm(@arr);
print "LCM is $ans";

---

Tips:

Find LCM of 2 numbers at a time, say lcm1. In next cycle, find lcm of lcm1 and next number and so on.

Quiz 36: Find GCD of multiple numbers

Problem:

Take N numbers as input and print their GCD

Input Format: 

num1 num2 num3......ie numbers seperated by space

Output Format: 
GCD

Constraints: 
none

Sample Input

6 15 9 30

Sample Output:
GCD is 3

Explanations:
3 is GCD of 6,15,9,30

---

Solution:

sub gcf {
my ($x, $y) = @_;
($x, $y) = ($y, $x % $y) while $y;
return $x;
}

sub multigcf {
      my $x = shift;
      $x = gcf($x, shift) while @_;
      return $x;
    }

chomp($num=<STDIN>);
@arr=split(" ",$num);
$ans=multigcf(@arr);
print "GCD is $ans";

---

Tips:

Find GCD of 2 numbers at a time, say gcd1. In next cycle, find gcd of gcd1 and next number and so on.

Quiz 35: Find LCM of 2 numbers

Problem:

Take 2 numbers as input and print their LCM

Input Format: 

number 1
number 2

Output Format: 
LCM

Constraints: 
none

Sample Input

15
20

Sample Output:
LCM is 60

Explanations:
60 is LCM of 15 and 20

---

Solution:

chomp($x=<STDIN>);
chomp($y=<STDIN>);
($a,$b) =($x,$y);
while($b)
{
($a, $b) = ($b, $a % $b)
}
$gcd=$a;
$lcm=($x*$y)/$gcd;
print "LCM is $lcm";

---

Tips:

LCM= product of numbers/GCD

Quiz 34: Find GCD of 2 numbers

Problem:

Take 2 numbers as input and print their GCD

Input Format: 

number 1
number 2

Output Format: 
GCD

Constraints: 
none

Sample Input

6
9

Sample Output:
GCD is 3

Explanations:
3 is GCD of 6 and 9

---

Solution:

chomp($a=<STDIN>);
chomp($b=<STDIN>);
while($b)
{
($a, $b) = ($b, $a % $b)
}
print "GCD is $a";

---

Tips:

Learn the logic of GCD