What is the real approach to solve this problem?

Question

https://code.sololearn.com/ciFdWfJi3ZFJ/?ref=app
https://www.hackerrank.com/challenges/30-dictionaries-and-maps/problem

Answer 1

Iutsavsingh
( 1 )

The code is working. It is just that
sys.stdin.readlines() takes the input but the list will only consist of one element.

For example, my Inputs are:

2
a b
c d
a b c d

2 is the n which indicates the number of pairs.
"a b" and "c d" are my two pairs.
"a b c d" is assigned to "lines"

But I tried to print the "lines" variable and I got ["a b c d"] which means that it is taking the input but the list will only consist of one element.

Although this input will work or return True:

2
a b
c d
a

This will return a=a.

But remember that when using "membership in" in a dictionary, we are using its keys instead of its values. If you want to use the value then just use
if x in dict.values():

Answer 2

( 2 )

If you want this input to work:

2 <--- no. of pairs
a b <--- pair1
c d <--- pair2
a c <--- lines variable

# Here we want to find if "a" is a key in phoneBook and if "c" is a key in phoneBook.

Then your iteration or for loop should be like this:

for i in lines[0]:
// code

- - - - - Comparison - - - - - -
for x in lines:
print(x)
>> a c

for x in lines[0]:
print(x)
>> a
>> c

Answer 3

Can you clarify what sys.stdin.readlines() does?

Cause I had already imported the sys module and print the "lines" variable but I got an empty list. Thanks.

Answer 4

《 Nicko12 》 It will use for taking input from the user also used for reading escape character

Answer 5

《 Nicko12 》 done!
I was not used import sys in top