Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Length of longest substring that do not contain any palindrome
In C++, we have predefined function max() that will be used for finding any longest substring that does contain any palindrome. A palindrome string is a group of characters that remains the same even after reversing.
Let’s take an example of a palindrome string to make the longest non-palindrome substring.
The string malayalam itself is a palindrome but we need to identify the longest non-palindrome substring. When we change the string malayalam( length=9 ) to alayalam then we get the longest non-palindrome substring length i.e, 8.
The string synapse is a non-palindrome string and its length is 7.
Syntax
The following syntax is used in the program −
substr( size_a position, size_a length )
Parameters
size_a − Thie integer type.
position −- The first character of the position is to be copied.
Length − The length of the substring.
var_name = max( var_name, size_a length)
Parameters
var_name − The name of the variable.
size_a − The integer type.
length − The length of the substring.
Algorithm
We will create a global function named ‘isPalindrome’ and pass the string 's' as a parameter to that function.
In the global function ‘isPalindrome’ we are calculating the length of string ‘s’ as input and storing it in a variable ‘n’ and using for loop the string character ‘s’ iterate from the first to the middle character.
Then we will create an if-statement to check whether both ‘(i)-th’ and ‘(num-i-1)-th’ characters are equivalent or not and return false if it is a palindrome otherwise return true.
In the main function we will define the variable ‘str’ and store the input string in it. Then find the length of ‘str’ and store it in another variable named ‘n’.
We are storing 0 in an integer variable ‘answer’ as it will be used for finding the length of the non-palindrome substring.
Start two nested for loops to iterate all possible substrings of str.
Use an if statement under the second for loop to call the above function named ‘isPalindrome’ for each substring.
We are finding the length of longest non-palindrome substring with the help of predefined function max(relate step 5).
Finally, the for nested loop counter will check if the substring is a non-palindrome or palindrome and then print the length of the longest substring of non-palindrome string.
Example
In this example, we follow the above algorithm's entire approach to learn how to find the length of the longest substring that does not contain a palindrome.
#include<iostream>
#include<algorithm>
using namespace std;
bool isPalindrome(string s) {
int n = s.length();
for (int i = 0; i < n/2; i++) {
if (s[i] != s[n-i-1]) {
return false;
}
}
return true;
}
int main() {
string str = "madam";
// “madam” string is itself a palindrome but its longest substring check so that it doesn’t become a palindrome and give its length in the output.
int n = str.length();
int answer = 0;
for (int i = 0; i < n; i++) {
for (int j = i+1; j <= n; j++) {
if (!isPalindrome(str.substr(i, j-i))) {
answer = max(answer, j-i);
// return the maximum length of non-palindrome substring.
}
}
}
cout << "The length of longest substring that does not contain any palindrome: "<<answer << endl;
return 0;
}
Output
The length of longest substring that does not contain any palindrome: 4
Conclusion
We have explored the concept of finding the length of the longest substring that does not contain any palindrome. Our analysis has observed that this problem can be approached by breaking it down into smaller sub-problems. This is also a real-life problem that has practical applications in fields such as natural language processing and bioinformatics.
198 Views
