# Length of the longest substring that do not contain any palindrome

Given a string of lowercase, find the length of the longest substring that does not contain any palindrome as a substring.

Examples:

```Input : str = "daiict"
Output : 3
dai, ict are longest substring that do not contain any
palindrome as substring

Input : str = "a"
Output : 0
a is itself a palindrome
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

The idea is to observe that if any character forms a palindrome, it can not be included in any substring. So, in that case required substring will be picked from before or after that character which forms a palindrome.

Therefore, a simple solution is to traverse the string and for each character check whether it forms a palindrome of length 2 or 3 with its adjacent characters. If, does not then increase the length of substring otherwise re-initialize the length of the substring to zero. Using this approach find the length of the maximum substring.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the above approach ` ` `  `#include ` `using` `namespace` `std; ` ` `  `// Function to find the length of the longest ` `// substring ` `int` `lenoflongestnonpalindrome(string s) ` `{ ` `    ``// initializing the variables ` `    ``int` `max1 = 1, len = 0; ` ` `  `    ``for` `(``int` `i = 0; i < s.length() - 1; i++) { ` `        ``// checking palindrome of size 2 ` `        ``// example: aa ` `        ``if` `(s[i] == s[i + 1]) ` `            ``len = 0; ` `        ``// checking palindrome of size 3 ` `        ``// example: aba ` `        ``else` `if` `(s[i + 1] == s[i - 1] && i > 0) ` `            ``len = 1; ` `        ``else` `// incrementing length of substring ` `            ``len++; ` `        ``max1 = max(max1, len + 1); ``// finding maximum ` `    ``} ` ` `  `    ``// if there exits single character then ` `    ``// it is always palindrome ` `    ``if` `(max1 == 1) ` `        ``return` `0; ` `    ``else` `        ``return` `max1; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``string s = ``"synapse"``; ` `    ``cout << lenoflongestnonpalindrome(s) << ``"\n"``; ` `    ``return` `0; ` `} `

## Java

 `// Java implementation of the above approach ` `import` `java.util.Arrays; ` `import` `java.lang.Math; ` ` `  `class` `GFG { ` ` `  `    ``// Function to find the length of the longest ` `    ``// substring ` `    ``public` `static` `int` `lenoflongestnonpalindrome(String s) ` `    ``{ ` `        ``// initializing the variables ` `        ``int` `max1 = ``1``, len = ``0``; ` `        ``char``[] new_str = s.toCharArray(); ` ` `  `        ``for` `(``int` `i = ``0``; i < new_str.length - ``1``; i++) { ` `            ``// checking palindrome of size 2 ` `            ``// example: aa ` `            ``if` `(new_str[i] == new_str[i + ``1``]) ` `                ``len = ``0``; ` `            ``// checking palindrome of size 3 ` `            ``// example: aba ` `            ``else` `if` `(i > ``0` `&& (new_str[i + ``1``] == new_str[i - ``1``])) ` `                ``len = ``1``; ` `            ``else` `// incrementing length of substring ` `                ``len++; ` `            ``max1 = Math.max(max1, len + ``1``); ``// finding maximum ` `        ``} ` ` `  `        ``// if there exits single character then ` `        ``// it is always palindrome ` `        ``if` `(max1 == ``1``) ` `            ``return` `0``; ` `        ``else` `            ``return` `max1; ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` `        ``String s = ``"synapse"``; ` `        ``System.out.println(lenoflongestnonpalindrome(s)); ` `    ``} ` `} ` ` `  `// This code is contributed by princiraj1992 `

## Python3

 `# Python3 implementation of the above approach  ` ` `  `# Function to find the length  ` `# of the longest substring  ` `def` `lenoflongestnonpalindrome(s):  ` ` `  `    ``# initializing the variables  ` `    ``max1, length ``=` `1``, ``0` ` `  `    ``for` `i ``in` `range``(``0``, ``len``(s) ``-` `1``):  ` `         `  `        ``# checking palindrome of  ` `        ``# size 2 example: aa  ` `        ``if` `s[i] ``=``=` `s[i ``+` `1``]:  ` `            ``length ``=` `0` `             `  `        ``# checking palindrome of  ` `        ``# size 3 example: aba  ` `        ``elif` `s[i ``+` `1``] ``=``=` `s[i ``-` `1``] ``and` `i > ``0``: ` `            ``length ``=` `1` `        ``else``: ``# incrementing length of substring  ` `            ``length ``+``=` `1` `        ``max1 ``=` `max``(max1, length ``+` `1``) ``# finding maximum  ` ` `  `    ``# If there exits single character  ` `    ``# then it is always palindrome  ` `    ``if` `max1 ``=``=` `1``:  ` `        ``return` `0` `    ``else``: ` `        ``return` `max1  ` ` `  `# Driver Code  ` `if` `__name__ ``=``=` `"__main__"``: ` ` `  `    ``s ``=` `"synapse"` `    ``print``(lenoflongestnonpalindrome(s)) ` `     `  `# This code is contributed by Rituraj Jain `

## C#

 `// C# implementation of the above approach  ` `using` `System; ` `     `  `class` `GFG  ` `{ ` ` `  `    ``// Function to find the length of the longest ` `    ``// substring ` `    ``public` `static` `int` `lenoflongestnonpalindrome(String s) ` `    ``{ ` `        ``// initializing the variables ` `        ``int` `max1 = 1, len = 0; ` `        ``char``[] new_str = s.ToCharArray(); ` ` `  `        ``for` `(``int` `i = 0; i < new_str.Length - 1; i++)  ` `        ``{ ` `            ``// checking palindrome of size 2 ` `            ``// example: aa ` `            ``if` `(new_str[i] == new_str[i + 1]) ` `                ``len = 0; ` `                 `  `            ``// checking palindrome of size 3 ` `            ``// example: aba ` `            ``else` `if` `(i > 0 && (new_str[i + 1] == new_str[i - 1])) ` `                ``len = 1; ` `            ``else` `// incrementing length of substring ` `                ``len++; ` `            ``max1 = Math.Max(max1, len + 1); ``// finding maximum ` `        ``} ` ` `  `        ``// if there exits single character then ` `        ``// it is always palindrome ` `        ``if` `(max1 == 1) ` `            ``return` `0; ` `        ``else` `            ``return` `max1; ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `Main(String[] args) ` `    ``{ ` `        ``String s = ``"synapse"``; ` `        ``Console.WriteLine(lenoflongestnonpalindrome(s)); ` `    ``} ` `} ` ` `  `// This code has been contributed by 29AjayKumar `

## PHP

 ` 0)  ` `            ``\$len` `= 1;  ` `        ``else` `// incrementing length of substring  ` `            ``\$len``++;  ` `        ``\$max1` `= max(``\$max1``, ``\$len` `+ 1); ``// finding maximum  ` `    ``}  ` ` `  `    ``// if there exits single character then  ` `    ``// it is always palindrome  ` `    ``if` `(``\$max1` `== 1)  ` `        ``return` `0;  ` `    ``else` `        ``return` `\$max1``;  ` `}  ` ` `  `// Driver Code  ` `\$s` `= ``"synapse"``;  ` `echo` `lenoflongestnonpalindrome(``\$s``), ``"\n"``;  ` ` `  `// This code is contributed by AnkitRai01 ` ` `  `?> `

Output:

```7
```

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