Given string str, the task is to check whether the given string contains 3 or more consecutive identical characters/numbers or not by using Regular Expression.
Examples:
Input: str = “aaa”;
Output: true
Explanation:
The given string contains a, a, a which are consecutive identical characters.
Input: str = “abc”;
Output: false
Explanation:
The given string contains a, b, c which are not consecutive identical characters.
Input: str = “11”;
Output: false
Explanation:
The given string contains 1, 1 which are not 3 or more consecutive identical numbers.
Approach: The idea is to use Regular Expression to solve this problem. The following steps can be followed to compute the answer.
- Get the String.
- Create a regular expression to check 3 or more consecutive identical characters or numbers as mentioned below:
regex = “\\b([a-zA-Z0-9])\\1\\1+\\b”;
- Where:
- \\b represents the word boundary.
- ( represents the starting of the group 1.
- [a-zA-Z0-9] represents a letter or a digit.
- ) represents the ending of the group 1.
- \\1 represents the same character as group 1.
- \\1+ represents the same character as group 1 one or more times.
- \\b represents the word boundary.
- Match the given string with the Regular Expression. In Java, this can be done by using Pattern.matcher().
- Return true if the string matches with the given regular expression, else return false.
Below is the implementation of the above approach:
// C++ program to check // three or more consecutive identical // characters or numbers using Regular Expression #include <iostream> #include <regex> using namespace std;
// Function to check three or more // consecutive identical characters or numbers. bool isIdentical(string str)
{ // Regex to check valid three or more
// consecutive identical characters or numbers.
const regex pattern( "\\b([a-zA-Z0-9])\\1\\1+\\b" );
// If the three or more consecutive
// identical characters or numbers
// is empty return false
if (str.empty())
{
return false ;
}
// Return true if the three or more
// consecutive identical characters or numbers
// matched the ReGex
if (regex_match(str, pattern))
{
return true ;
}
else
{
return false ;
}
} // Driver Code int main()
{ // Test Case 1:
string str1 = "aaa" ;
cout << isIdentical(str1) << endl;
// Test Case 2:
string str2 = "11111" ;
cout << isIdentical(str2) << endl;
// Test Case 3:
string str3 = "aaab" ;
cout << isIdentical(str3) << endl;
// Test Case 4:
string str4 = "abc" ;
cout << isIdentical(str4) << endl;
// Test Case 5:
string str5 = "aa" ;
cout << isIdentical(str5) << endl;
return 0;
} // This code is contributed by yuvraj_chandra |
// Java program to check three or // more consecutive identical // characters or numbers // using regular expression import java.util.regex.*;
class GFG {
// Function to check three or
// more consecutive identical
// characters or numbers
// using regular expression
public static boolean isIdentical(String str)
{
// Regex to check three or
// more consecutive identical
// characters or numbers
String regex
= "\\b([a-zA-Z0-9])\\1\\1+\\b" ;
// Compile the ReGex
Pattern p
= Pattern.compile(regex);
// If the string is empty
// return false
if (str == null ) {
return false ;
}
// Find match between given string
// and regular expression
// using Pattern.matcher()
Matcher m = p.matcher(str);
// Return if the string
// matched the ReGex
return m.matches();
}
// Driver code
public static void main(String args[])
{
// Test Case 1:
String str1 = "aaa" ;
System.out.println(
isIdentical(str1));
// Test Case 2:
String str2 = "11111" ;
System.out.println(
isIdentical(str2));
// Test Case 3:
String str3 = "aaab" ;
System.out.println(
isIdentical(str3));
// Test Case 4:
String str4 = "abc" ;
System.out.println(
isIdentical(str4));
// Test Case 5:
String str5 = "aa" ;
System.out.println(
isIdentical(str5));
}
} |
# Python3 program to check three or # more consecutiveidentical # characters or numbers # using regular expression import re
# Function to check three or # more consecutiveidentical # characters or numbers # using regular expression def isValidGUID( str ):
# Regex to check three or
# more consecutive identical
# characters or numbers
regex = "\\b([a-zA-Z0-9])\\1\\1+\\b"
# Compile the ReGex
p = re. compile (regex)
# If the string is empty
# return false
if ( str = = None ):
return False
# Return if the string
# matched the ReGex
if (re.search(p, str )):
return True
else :
return False
# Driver code # Test Case 1: str1 = "aaa"
print (isValidGUID(str1))
# Test Case 2: str2 = "11111"
print (isValidGUID(str2))
# Test Case 3: str3 = "aaab"
print (isValidGUID(str3))
# Test Case 4: str4 = "abc"
print (isValidGUID(str4))
# Test Case 4: str5 = "aa"
print (isValidGUID(str5))
# This code is contributed by avanitrachhadiya2155 |
// C# program to check three or // more consecutive identical // characters or numbers // using regular expression using System;
using System.Text.RegularExpressions;
class GFG {
// Function to check three or
// more consecutive identical
// characters or numbers
// using regular expression
public static bool isIdentical( string str)
{
// Regex to check three or
// more consecutive identical
// characters or numbers
string regex
= "\\b([a-zA-Z0-9])\\1\\1+\\b" ;
// Compile the ReGex
Regex p = new Regex(regex);
// If the string is empty
// return false
if (str == null ) {
return false ;
}
// Find match between given string
// and regular expression
// using Pattern.matcher()
Match m = p.Match(str);
// Return if the string
// matched the ReGex
return m.Success;
}
// Driver code
public static void Main()
{
// Test Case 1:
string str1 = "aaa" ;
Console.WriteLine(
isIdentical(str1));
// Test Case 2:
string str2 = "11111" ;
Console.WriteLine(
isIdentical(str2));
// Test Case 3:
string str3 = "aaab" ;
Console.WriteLine(
isIdentical(str3));
// Test Case 4:
string str4 = "abc" ;
Console.WriteLine(
isIdentical(str4));
// Test Case 5:
string str5 = "aa" ;
Console.WriteLine(
isIdentical(str5));
}
} // This code is contributed by Aman Kumar. |
// Javascript program to check // three or more consecutive identical // characters or numbers using Regular Expression // Function to check three or more // consecutive identical characters or numbers. function isIdentical(str)
{ // Regex to check valid three or more // consecutive identical characters or numbers. let pattern = new RegExp( "\\b([a-zA-Z0-9])\\1\\1+\\b" );
// If the three or more consecutive // identical characters or numbers // is empty return false if (str== null )
{ return false ;
} // Return true if the three or more // consecutive identical characters or numbers // matched the ReGex if (pattern.test(str)== true )
{ return true ;
} else { return false ;
} } // Driver Code // Test Case 1: let str1 = "aaa" ;
console.log(isIdentical(str1)+ "<br>" );
// Test Case 2: let str2 = "11111" ;
console.log(isIdentical(str2)+ "<br>" );
// Test Case 3: let str3 = "aaab" ;
console.log(isIdentical(str3)+ "<br>" );
// Test Case 4: let str4 = "abc" ;
console.log(isIdentical(str4)+ "<br>" );
// Test Case 5: let str5 = "aa" ;
console.log(isIdentical(str5)+ "<br>" );
// This code is contributed by Pushpesh Raj. |
true true false false false