Program to validate an IP address
Write a program to Validate an IPv4 Address.
According to Wikipedia, IPv4 addresses are canonically represented in dot-decimal notation, which consists of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1
Following are steps to check whether a given string is a valid IPv4 address or not:
step 1) Parse string with “.” as delimiter using “strtok()” function.
e.g.ptr = strtok(str, DELIM);
step 2)
A) If ptr contains any character which is not digit then return 0
B) Convert “ptr” to decimal number say ‘NUM’
C) If NUM is not in range of 0-255 return 0
D) If NUM is in range of 0-255 and ptr is non-NULL increment “dot_counter” by 1
E) if ptr is NULL goto step 3 else goto step 1
step 3) if dot_counter != 3 return 0 else return 1
C++
// Program to check if a given // string is valid IPv4 address or not #include <bits/stdc++.h> using namespace std; #define DELIM "." /* function to check whether the string passed is valid or not */ bool valid_part( char * s) { int n = strlen (s); // if length of passed string is // more than 3 then it is not valid if (n > 3) return false ; // check if the string only contains digits // if not then return false for ( int i = 0; i < n; i++) if ((s[i] >= '0' && s[i] <= '9' ) == false ) return false ; string str(s); // if the string is "00" or "001" or // "05" etc then it is not valid if (str.find( '0' ) == 0 && n > 1) return false ; stringstream geek(str); int x; geek >> x; // the string is valid if the number // generated is between 0 to 255 return (x >= 0 && x <= 255); } /* return 1 if IP string is valid, else return 0 */ int is_valid_ip( char * ip_str) { // if empty string then return false if (ip_str == NULL) return 0; int i, num, dots = 0; int len = strlen (ip_str); int count = 0; // the number dots in the original // string should be 3 // for it to be valid for ( int i = 0; i < len; i++) if (ip_str[i] == '.' ) count++; if (count != 3) return false ; // See following link for strtok() char *ptr = strtok (ip_str, DELIM); if (ptr == NULL) return 0; while (ptr) { /* after parsing string, it must be valid */ if (valid_part(ptr)) { /* parse remaining string */ ptr = strtok (NULL, "." ); if (ptr != NULL) ++dots; } else return 0; } /* valid IP string must contain 3 dots */ // this is for the cases such as 1...1 where // originally the no. of dots is three but // after iteration of the string we find // it is not valid if (dots != 3) return 0; return 1; } // Driver code int main() { char ip1[] = "128.0.0.1" ; char ip2[] = "125.16.100.1" ; char ip3[] = "125.512.100.1" ; char ip4[] = "125.512.100.abc" ; is_valid_ip(ip1) ? cout<< "Valid\n" : cout<< "Not valid\n" ; is_valid_ip(ip2) ? cout<< "Valid\n" : cout<< "Not valid\n" ; is_valid_ip(ip3) ? cout<< "Valid\n" : cout<< "Not valid\n" ; is_valid_ip(ip4) ? cout<< "Valid\n" : cout<< "Not valid\n" ; return 0; } |
C
#include <stdbool.h> #include <stdio.h> #include <string.h> #define DELIM "." /* function to check whether the string passed is valid or not */ bool valid_part( const char * s) { int n = strlen (s); // if length of passed string is // more than 3 then it is not valid if (n > 3) return false ; // check if the string only contains digits // if not then return false for ( int i = 0; i < n; i++) if (s[i] < '0' || s[i] > '9' ) return false ; int x = atoi (s); // the string is valid if the number // generated is between 0 to 255 return (x >= 0 && x <= 255); } /* return 1 if IP string is valid, else return 0 */ int is_valid_ip( char * ip_str) { // if empty string then return false if (ip_str == NULL) return 0; int num, dots = 0; int len = strlen (ip_str); int count = 0; // the number dots in the original // string should be 3 // for it to be valid for ( int i = 0; i < len; i++) if (ip_str[i] == '.' ) count++; if (count != 3) return false ; // See following link for strtok() char * ptr = strtok (ip_str, DELIM); if (ptr == NULL) return 0; while (ptr) { /* after parsing string, it must be valid */ if (valid_part(ptr)) { /* parse remaining string */ ptr = strtok (NULL, "." ); if (ptr != NULL) ++dots; } else return 0; } /* valid IP string must contain 3 dots */ // this is for the cases such as 1...1 where // originally the no. of dots is three but // after iteration of the string we find // it is not valid if (dots != 3) return 0; return 1; } // Driver code int main() { char ip1[] = "128.0.0.1" ; char ip2[] = "125.16.100.1" ; char ip3[] = "125.512.100.1" ; char ip4[] = "125.512.100.abc" ; is_valid_ip(ip1) ? printf ( "Valid\n" ) : printf ( "Not valid\n" ); is_valid_ip(ip2) ? printf ( "Valid\n" ) : printf ( "Not valid\n" ); is_valid_ip(ip3) ? printf ( "Valid\n" ) : printf ( "Not valid\n" ); is_valid_ip(ip4) ? printf ( "Valid\n" ) : printf ( "Not valid\n" ); return 0; } |
Java
import java.util.StringTokenizer; public class Main { static final String DELIM = "." ; // Function to check whether the string passed is valid or not static boolean isValidPart(String s) { int n = s.length(); // If the length of the string is more than 3, then it is not valid if (n > 3 ) return false ; // Check if the string only contains digits // If not, then return false for ( int i = 0 ; i < n; i++) if (!(s.charAt(i) >= '0' && s.charAt(i) <= '9' )) return false ; // If the string is "00" or "001" or "05" etc then it is not valid if (s.indexOf( '0' ) == 0 && n > 1 ) return false ; try { int x = Integer.parseInt(s); // The string is valid if the number generated is between 0 to 255 return (x >= 0 && x <= 255 ); } catch (NumberFormatException e) { return false ; } } // Return 1 if IP string is valid, else return 0 static int isValidIP(String ipStr) { // If the empty string then return false if (ipStr == null ) return 0 ; int dots = 0 ; int len = ipStr.length(); int count = 0 ; // The number dots in the original string should be 3 // for it to be valid for ( int i = 0 ; i < len; i++) if (ipStr.charAt(i) == '.' ) count++; if (count != 3 ) return 0 ; // Using StringTokenizer to split the IP string StringTokenizer st = new StringTokenizer(ipStr, DELIM); while (st.hasMoreTokens()) { String part = st.nextToken(); // After parsing string, it must be valid if (isValidPart(part)) { // Parse remaining string if (st.hasMoreTokens()) dots++; } else return 0 ; } // Valid IP string must contain 3 dots // This is for cases such as 1...1 where // originally the number of dots is three but // after iteration of the string, we find it is not valid if (dots != 3 ) return 0 ; return 1 ; } // Driver code public static void main(String[] args) { String ip1 = "128.0.0.1" ; String ip2 = "125.16.100.1" ; String ip3 = "125.512.100.1" ; String ip4 = "125.512.100.abc" ; System.out.println(isValidIP(ip1) == 1 ? "Valid" : "Not valid" ); System.out.println(isValidIP(ip2) == 1 ? "Valid" : "Not valid" ); System.out.println(isValidIP(ip3) == 1 ? "Valid" : "Not valid" ); System.out.println(isValidIP(ip4) == 1 ? "Valid" : "Not valid" ); } } |
Python3
# Function to check whether the string passed is valid or not def valid_part(s): n = len (s) # If the length of the passed string is more than 3, it is not valid if n > 3 : return False # Check if the string only contains digits, if not, return false for i in range (n): if not s[i].isdigit(): return False # Convert the string to an integer x = int (s) # The string is valid if the number generated is between 0 to 255 return 0 < = x < = 255 # Return True if the IP string is valid, else return False def is_valid_ip(ip_str): # If the string is empty, return False if ip_str is None : return False parts = ip_str.split( '.' ) count = 0 # The number of dots in the original string should be 3 for it to be valid for i in range ( len (ip_str)): if ip_str[i] = = '.' : count + = 1 if count ! = 3 : return False for part in parts: if not valid_part(part): return False return True # Driver code ip1 = "128.0.0.1" ip2 = "125.16.100.1" ip3 = "125.512.100.1" ip4 = "125.512.100.abc" # Check and print whether the IPs are valid or not print ( "Valid" if is_valid_ip(ip1) else "Not valid" ) print ( "Valid" if is_valid_ip(ip2) else "Not valid" ) print ( "Valid" if is_valid_ip(ip3) else "Not valid" ) print ( "Valid" if is_valid_ip(ip4) else "Not valid" ) |
C#
// Program to check if a given // string is valid IPv4 address or not using System; using System.Text.RegularExpressions; class Program { /* function to check whether the string passed is valid or not */ static bool ValidPart( string s) { int n = s.Length; // if length of passed string is // more than 3 then it is not valid if (n > 3) return false ; // check if the string only contains digits // if not then return false for ( int i = 0; i < n; i++) { if (!(s[i] >= '0' && s[i] <= '9' )) return false ; } string str = s; // if the string is "00" or "001" or // "05" etc then it is not valid if (str.IndexOf( '0' ) == 0 && n > 1) return false ; // the string is valid if the number // generated is between 0 to 255 if ( int .TryParse(str, out int x)) { return (x >= 0 && x <= 255); } return false ; } /* return 1 if IP string is valid, else return 0 */ static int IsValidIP( string ipStr) { // if empty string then return false if (ipStr == null ) return 0; int count = 0; int len = ipStr.Length; // the number dots in the original // string should be 3 // for it to be valid for ( int i = 0; i < len; i++) { if (ipStr[i] == '.' ) { count++; } } if (count != 3) { return 0; } string [] parts = ipStr.Split( '.' ); if (parts.Length != 4) { return 0; } foreach ( string part in parts) { if (!ValidPart(part)) { return 0; } } return 1; } static void Main( string [] args) { string ip1 = "128.0.0.1" ; string ip2 = "125.16.100.1" ; string ip3 = "125.512.100.1" ; string ip4 = "125.512.100.abc" ; Console.WriteLine( IsValidIP(ip1) == 1 ? "Valid" : "Not valid" ); Console.WriteLine( IsValidIP(ip2) == 1 ? "Valid" : "Not valid" ); Console.WriteLine( IsValidIP(ip3) == 1 ? "Valid" : "Not valid" ); Console.WriteLine( IsValidIP(ip4) == 1 ? "Valid" : "Not valid" ); } } |
Javascript
// Function to check whether the string passed is valid or not function validPart(s) { const n = s.length; // If the length of the passed string is more than 3, it is not valid if (n > 3) { return false ; } // Check if the string only contains digits, if not, return false for (let i = 0; i < n; i++) { if (!(s[i] >= '0' && s[i] <= '9' )) { return false ; } } // Convert the string to an integer const x = parseInt(s); // The string is valid if the number generated is between 0 to 255 return (x >= 0 && x <= 255); } // Return true if the IP string is valid, else return false function isValidIP(ipStr) { // If the string is empty, return false if (ipStr === null ) { return false ; } const parts = ipStr.split( '.' ); let count = 0; // The number of dots in the original string should be 3 for it to be valid for (let i = 0; i < ipStr.length; i++) { if (ipStr[i] === '.' ) { count++; } } if (count !== 3) { return false ; } for (let i = 0; i < parts.length; i++) { if (!validPart(parts[i])) { return false ; } } return true ; } // Driver code const ip1 = "128.0.0.1" ; const ip2 = "125.16.100.1" ; const ip3 = "125.512.100.1" ; const ip4 = "125.512.100.abc" ; isValidIP(ip1) ? console.log( "Valid" ) : console.log( "Not valid" ); isValidIP(ip2) ? console.log( "Valid" ) : console.log( "Not valid" ); isValidIP(ip3) ? console.log( "Valid" ) : console.log( "Not valid" ); isValidIP(ip4) ? console.log( "Valid" ) : console.log( "Not valid" ); |
Valid Valid Not valid Not valid
Time complexity : O(n)
Auxiliary Space : O(1)
This article is compiled by Narendra Kangralkar. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
Python Solution :-
Approach:- We will check all the cases where ip address may be invalid
1. First we will split the given input using split() function then check if it has a length of 4 or not .If length is not equal to 4 then we will directly return 0.
2. in second step we will check if any split element contains any leading zero or not .if it is then we will return zero.
3.If any of the split does not contain any number then it is not a valid ip address .so we will return 0
4. Then we will check if all the splits are in the range of 0-255 or not .If not we will return 0.
5.Finally if none of the above condition is true we can finally say that it is a valid ip address.And we will return True.
Here is the code for above approach .
C++
#include <iostream> #include <sstream> // Function to check if a number is in the range 0-255 bool inRange( int n) { return (n >= 0 && n <= 255); } // Function to check if a string has a leading zero bool hasLeadingZero( const std::string& n) { if (n.length() > 1) { if (n[0] == '0' ) { return true ; } } return false ; } // Function to validate an IP address string int isValid( const std::string& s) { // Using stringstream to split the string by '.' std::istringstream ss(s); std::string part; int count = 0; // Loop through each part of the IP address while (getline(ss, part, '.' )) { count++; // Check for leading zeros in each part if (hasLeadingZero(part)) { return 0; // Invalid if leading zero is present } // Check if part is empty if (part.length() == 0) { return 0; // Invalid if part is empty } // Try converting the part to an integer try { int num = std::stoi(part); // Check if the integer is in the valid range if (!inRange(num)) { return 0; // Invalid if not in the range 0-255 } } catch (std::invalid_argument const & e) { return 0; // Invalid if conversion to integer fails } } // Check if there are exactly 4 parts in the IP address return (count == 4) ? 1 : 0; } int main() { // Test IP addresses std::string ip1 = "222.111.111.111" ; std::string ip2 = "5555..555" ; std::string ip3 = "0000.0000.0000.0000" ; std::string ip4 = "1.1.1.1" ; // Print the validation result for each IP address std::cout << isValid(ip1) << std::endl; std::cout << isValid(ip2) << std::endl; std::cout << isValid(ip3) << std::endl; std::cout << isValid(ip4) << std::endl; return 0; } |
Java
public class GFG { public static boolean inRange( int n) { // check if every split is in range 0-255 if (n >= 0 && n <= 255 ) { return true ; } return false ; } public static boolean hasLeadingZero(String n) { // check if every split has leading zero or not. if (n.length() > 1 ) { if (n.charAt( 0 ) == '0' ) { return true ; } } return false ; } public static int isValid(String s) { String[] parts = s.split( "\\." ); if (parts.length != 4 ) { // if number of splitting element is not // 4 it is not a valid IP address return 0 ; } for (String part : parts) { if (hasLeadingZero(part)) { return 0 ; } if (part.length() == 0 ) { return 0 ; } try { int num = Integer.parseInt(part); if (!inRange(num)) { return 0 ; } } catch (NumberFormatException e) { return 0 ; } } return 1 ; } public static void main(String[] args) { String ip1 = "222.111.111.111" ; String ip2 = "5555..555" ; String ip3 = "0000.0000.0000.0000" ; String ip4 = "1.1.1.1" ; System.out.println(isValid(ip1)); System.out.println(isValid(ip2)); System.out.println(isValid(ip3)); System.out.println(isValid(ip4)); } } |
Python3
def in_range(n): #check if every split is in range 0-255 if n > = 0 and n< = 255 : return True return False def has_leading_zero(n): # check if every split has leading zero or not. if len (n)> 1 : if n[ 0 ] = = "0" : return True return False def isValid(s): s = s.split( "." ) if len (s) ! = 4 : #if number of splitting element is not 4 it is not a valid ip address return 0 for n in s: if has_leading_zero(n): return 0 if len (n) = = 0 : return 0 try : #if int(n) is not an integer it raises an error n = int (n) if not in_range(n): return 0 except : return 0 return 1 if __name__ = = "__main__" : ip1 = "222.111.111.111" ip2 = "5555..555" ip3 = "0000.0000.0000.0000" ip4 = "1.1.1.1" print (isValid(ip1)) print (isValid(ip2)) print (isValid(ip3)) print (isValid(ip4)) # this code is contributed by Vivek Maddeshiya. |
C#
using System; class GFG { // Function to check if a number is in the range 0-255 static bool InRange( int n) { return (n >= 0 && n <= 255); } // Function to check if a string has a leading zero static bool HasLeadingZero( string n) { if (n.Length > 1 && n[0] == '0' ) { return true ; } return false ; } // Function to validate an IP address string static int IsValid( string s) { // Split the string by '.' string [] parts = s.Split( '.' ); int count = 0; // Loop through each part of the IP address foreach ( string part in parts) { count++; // Check for leading zeros in each part if (HasLeadingZero(part)) { return 0; // Invalid if leading zero is present } // Check if part is empty if (part.Length == 0) { return 0; // Invalid if part is empty } // Try converting the part to an integer if (! int .TryParse(part, out int num)) { return 0; // Invalid if conversion to integer fails } // Check if the integer is in the valid range if (!InRange(num)) { return 0; // Invalid if not in the range 0-255 } } // Check if there are exactly 4 parts in the IP address return (count == 4) ? 1 : 0; } static void Main() { // Test IP addresses string ip1 = "222.111.111.111" ; string ip2 = "5555..555" ; string ip3 = "0000.0000.0000.0000" ; string ip4 = "1.1.1.1" ; // Print the validation result for each IP address Console.WriteLine(IsValid(ip1)); Console.WriteLine(IsValid(ip2)); Console.WriteLine(IsValid(ip3)); Console.WriteLine(IsValid(ip4)); } } |
Javascript
function inRange(n) { // check if every split is in range 0-255 if (n >= 0 && n <= 255) { return true ; } return false ; } function hasLeadingZero(n) { // check if every split has leading zero or not. if (n.length > 1) { if (n.charAt(0) === '0' ) { return true ; } } return false ; } function isValid(s) { let parts = s.split( '.' ); if (parts.length !== 4) { // if number of splitting element is not 4 it is not a valid IP address return 0; } for (let i = 0; i < parts.length; i++) { let part = parts[i]; if (hasLeadingZero(part)) { return 0; } if (part.length === 0) { return 0; } try { let num = parseInt(part, 10); if (!inRange(num)) { return 0; } } catch (e) { return 0; } } return 1; } let ip1 = "222.111.111.111" ; let ip2 = "5555..555" ; let ip3 = "0000.0000.0000.0000" ; let ip4 = "1.1.1.1" ; console.log(isValid(ip1)); console.log(isValid(ip2)); console.log(isValid(ip3)); console.log(isValid(ip4)); |
1 0 0 1
Time complexity : O(n)
Auxiliary Space : O(1)
Method 3 – Using String stream and vector
Approach
- Using string stream to separate all the string from ‘.’ and push back into vector like for ex – 222.111.111.111 vector is v = [“222” , “111” , “111” , “111”]
- If the vector size != 4 return false, like 222.111.111.111 v = [“222” , “111” , “111” , “111”].
- Iterating over the generated vector of string
- for leading zero , test case like 222.0.0.10 this is valid but this is not 222.00.100.100 , we check for the size of the i th string if temp.size() > 1 and if(temp[0] == ‘0’) return false;
- For test case like a.b.c.d , checking the alpha values like abcde…… if any present simply return false
- And lastly we are checking if the number is greater than 255 or not
C++
// Program to check if a given // string is valid IPv4 address or not #include <bits/stdc++.h> using namespace std; /* return 1 if IP string is valid, else return 0 */ int is_valid_ip(string s) { // code here int n = s.size(); // for test case like 1...1 or something lesser than 7 if (n < 7) return false ; // Using string stream to separate all the string from // '.' and push back into vector like for ex - // 222.111.111.111 vector is v = ["222" , "111" , "111" // , "111"] vector<string> v; stringstream ss(s); while (ss.good()) { string substr; getline(ss, substr, '.' ); v.push_back(substr); } // If the vector size != 4 return false, like // 222.111.111.111 v = ["222" , "111" , "111" , // "111"]. if (v.size() != 4) return false ; // Iterating over the generated vector of string for ( int i = 0; i < v.size(); i++) { // string temp = v[i]; // for leading zero , test case like 222.0.0.10 this // is valid but this is not vaild 222.00.100.100 , we // check for the size of the i th string if // temp.size() > 1 and if(temp[0] == '0') return // false; if (temp.size() > 1) { if (temp[0] == '0' ) return false ; } // For test case like a.b.c.d , checking the alpha // values like abcde...... if any present simply // return false for ( int j = 0; j < temp.size(); j++) { if ( isalpha (temp[j])) return false ; } // And lastly we are checking if the number is // greater than 255 or not if (stoi(temp) > 255) return false ; } return true ; } // Driver code int main() { string s1 = "128.0.0.1" ; string s2 = "125.16.100.1" ; string s3 = "125.512.100.1" ; string s4 = "125.512.100.abc" ; is_valid_ip(s1) ? cout << "Valid\n" : cout << "Not valid\n" ; is_valid_ip(s2) ? cout << "Valid\n" : cout << "Not valid\n" ; is_valid_ip(s3) ? cout << "Valid\n" : cout << "Not valid\n" ; is_valid_ip(s4) ? cout << "Valid\n" : cout << "Not valid\n" ; return 0; } |
Java
import java.util.StringTokenizer; class Main { // Function to check if a given // string is a valid IPv4 address or not static boolean isValidIP(String s) { int n = s.length(); // for test cases like 1...1 or something lesser than 7 if (n < 7 ) return false ; // Using StringTokenizer to separate all the strings from // '.' and push back into vector like for example - // 222.111.111.111 vector is v = ["222", "111", "111", "111"] StringTokenizer st = new StringTokenizer(s, "." ); int count = 0 ; while (st.hasMoreTokens()) { String substr = st.nextToken(); count++; // If the substring size is greater than 1 and the first character is '0', return false if (substr.length() > 1 && substr.charAt( 0 ) == '0' ) return false ; // For substrings like a.b.c.d, checking if any character is non-numeric for ( int j = 0 ; j < substr.length(); j++) { if (!Character.isDigit(substr.charAt(j))) return false ; } // Check if the number is greater than 255 if (Integer.parseInt(substr) > 255 ) return false ; } // If the count of substrings is not 4, return false if (count != 4 ) return false ; return true ; } // Driver code public static void main(String[] args) { String s1 = "128.0.0.1" ; String s2 = "125.16.100.1" ; String s3 = "125.512.100.1" ; String s4 = "125.512.100.abc" ; System.out.println(isValidIP(s1) ? "Valid" : "Not valid" ); System.out.println(isValidIP(s2) ? "Valid" : "Not valid" ); System.out.println(isValidIP(s3) ? "Valid" : "Not valid" ); System.out.println(isValidIP(s4) ? "Valid" : "Not valid" ); } } |
Python
def is_valid_ip(s): n = len (s) # for test cases like 1...1 or something lesser than 7 if n < 7 : return False # Using split to separate all the strings from '.' # and create a list like for example - # "222.111.111.111" becomes ["222", "111", "111", "111"] substrings = s.split( "." ) count = 0 for substr in substrings: count + = 1 # If the substring size is greater than 1 and the first character is '0', return false if len (substr) > 1 and substr[ 0 ] = = '0' : return False # For substrings like a.b.c.d, checking if any character is non-numeric if not substr.isdigit(): return False # Check if the number is greater than 255 if int (substr) > 255 : return False # If the count of substrings is not 4, return false if count ! = 4 : return False return True # Driver code s1 = "128.0.0.1" s2 = "125.16.100.1" s3 = "125.512.100.1" s4 = "125.512.100.abc" print ( "Valid" if is_valid_ip(s1) else "Not valid" ) print ( "Valid" if is_valid_ip(s2) else "Not valid" ) print ( "Valid" if is_valid_ip(s3) else "Not valid" ) print ( "Valid" if is_valid_ip(s4) else "Not valid" ) |
C#
using System; using System.Collections.Generic; using System.Linq; using System.Text.RegularExpressions; class Program { /* Return true if IP string is valid, else return false */ static bool IsValidIP( string s) { int n = s.Length; // For test cases like 1...1 or something lesser than 7 if (n < 7) return false ; // Using regex to match and separate all the strings from '.' var matches = Regex.Matches(s, @"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b" ); // If the number of matches is not 1, return false if (matches.Count != 1) return false ; // Extract the matched IP string var ipString = matches[0].Value; // Split the IP string by '.' and store in an array string [] parts = ipString.Split( '.' ); // If the array length != 4, return false if (parts.Length != 4) return false ; // Iterating over the array of strings for ( int i = 0; i < parts.Length; i++) { string temp = parts[i]; // For leading zero, check if the string is "0" or starts with '0' if (temp.Length > 1 && temp[0] == '0' ) return false ; // For alphanumeric characters, return false if (temp.Any( char .IsLetter)) return false ; // Check if the number is greater than 255 if ( int .Parse(temp) > 255) return false ; } return true ; } // Driver code static void Main() { string s1 = "128.0.0.1" ; string s2 = "125.16.100.1" ; string s3 = "125.512.100.1" ; string s4 = "125.512.100.abc" ; Console.WriteLine(IsValidIP(s1) ? "Valid" : "Not valid" ); Console.WriteLine(IsValidIP(s2) ? "Valid" : "Not valid" ); Console.WriteLine(IsValidIP(s3) ? "Valid" : "Not valid" ); Console.WriteLine(IsValidIP(s4) ? "Valid" : "Not valid" ); } } |
Javascript
function isValidIP(s) { const n = s.length; if (n < 7) return false ; const v = s.split( '.' ); if (v.length !== 4) return false ; for (let i = 0; i < v.length; i++) { const temp = v[i]; if (temp.length > 1 && temp[0] === '0' ) return false ; for (let j = 0; j < temp.length; j++) { if (isNaN(temp[j])) return false ; } if (parseInt(temp) > 255) return false ; } return true ; } // Driver code const s1 = "128.0.0.1" ; const s2 = "125.16.100.1" ; const s3 = "125.512.100.1" ; const s4 = "125.512.100.abc" ; isValidIP(s1) ? console.log( "Valid" ) : console.log( "Not valid" ); isValidIP(s2) ? console.log( "Valid" ) : console.log( "Not valid" ); isValidIP(s3) ? console.log( "Valid" ) : console.log( "Not valid" ); isValidIP(s4) ? console.log( "Valid" ) : console.log( "Not valid" ); //This article is contributed by Utkarsh |
Valid Valid Not valid Not valid
Time complexity : O(n)
Auxiliary Space : O(1)
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