Program to validate IP address

Easy

0/40

Average time to solve is 15m

Contributed by

86 upvotes

Asked in companies

Problem statement

You are given the text ‘IPAddress’. Your task is to check if the given text ‘IPAddress’ is a valid ‘IPv4’ or not.

Conditions for a valid ‘IPv4’ are:

1. Text form of ‘IPAddress’ must be ‘a.b.c.d’
2. The values of a,b,c and d can vary from ‘0’ to ‘255’ and both ‘0’ and ‘255’ are inclusive.

Detailed explanation ( Input/output format, Notes, Images )

Input format:

The first line of input contains an integer ‘T’ denoting the number of test cases.

The next ‘T’ lines represent the ‘T’ test cases.

The first and only line of every test case contains a string ‘IPAddress’.

Output Format:

For each test case, print ‘True’ if the given text ‘IPAddress’ is valid ‘IPv4’ else print ‘False’.

Note:

You don’t have to print anything, it has already been taken care of. Just implement the given function.

Constraints:

1 <= T <= 10^4
1 <= length of given text <= 50

Time limit: 1 sec

Sample Input 1:

4
123.111.12.k
122.0.330.0
1.1.1.250
1.0.0.0.1

Sample Output 1:

False
False
True
False

Explanation of sample input 1:

Test Case 1:
Given text ‘IPAddress = 123.111.12.k’, it is satisfying the first condition that given ‘IPAddress’ must be ‘a.b.c.d’ formed but it not satisfying the second condition that d must in a range of ‘0’ to ‘255’ but the value of ‘d’ is ‘k’.
Hence return ‘False’.

Test Case 2:
Given text ‘IPAddress = 122.0.330.0’, it is satisfying the first condition that given ‘IPAddress’ must be ‘a.b.c.d’ formed but it not satisfying the second condition that c must in a range of ‘0’ to ‘255’ but the value of ‘c’ is ‘330’ and it is out of range.
Hence return ‘False’.

Test Case 3:
Given text ‘IPAddress = 1.1.1.250’, it is satisfying the first condition that given ‘IPAddress’ must be ‘a.b.c.d’ formed as well as it satisfying the second condition that a,b,c, and d must in range of ‘0’ to ‘250’.
Hence return ‘True’.

Test Case 4:
Given text ‘IPAddress = 1.0.0.0.1’, it is not satisfying the first condition for valid ‘IPv4’, that text ‘IPAddress’ must be in form of ‘a.b.c.d’ but given text is a form of ‘a.b.c.d.e’
Hence return ‘False’.

Sample Input 2:

2
1.90.21.1
1.1

Sample Output 2:

True
False

Hint 1

Hint 2

Try to think of a recursive approach.

Approaches (2)

Approach 1

Approach 2

Recursion

Idea is that, check every chunk is valid or not and the number of chunks is 4.

Suppose given ‘IPAddress’ in form of ‘a.b.c.d’.
Then first check for ‘a’ part that ‘a’ is valid ‘IPv4’ chunk or not, if ‘a’ part is valid then recursively check if the form remains part ‘b.c.d’.
Call ‘isValidChunk(chunk)’ its return given chunk is valid or not means if given ‘chunk’ is a string and its integer conversion is ‘0’ to ‘255’ then returns ‘True’ else ‘False’.
Call ‘helperMethod(IPAddress)’ which will return a number of chunks in ‘IPAddress’ of all chunks are valid otherwise its returns‘ -1’.
If the given ‘IPAddress’ has a total ‘4’ chunk then it's a valid ‘IPv4’, so return ‘True’.
If given ‘IPAddress’ has no ‘4’ chunks, return ‘False’

Time Complexity

O(1),

We are using a recursion of constant depth.

Space Complexity

O(1),

We are using constant space.

(100% EXP penalty)

Program to validate IP address

Console