Your browser (Unknown 0) is no longer supported. Some parts of the website may not work correctly. Please update your browser.

UPCOMING CHALLENGES:

CURRENT CHALLENGES:

Future Mobility

PAST CHALLENGES

Grand Challenge

Decoding Master

Digital Gold

Selenium 2018

Germanium 2018

Gallium 2018

Zinc 2018

Cuprum 2018

Cutting Complexity

Nickel 2018

Cobaltum 2018

Ferrum 2018

Manganum 2017

Chromium 2017

Vanadium 2016

Titanium 2016

Scandium 2016

Calcium 2015

Kalium 2015

Argon 2015

Chlorum 2014

Sulphur 2014

Phosphorus 2014

Silicium 2014

Aluminium 2014

Magnesium 2014

Natrium 2014

Neon 2014

Fluorum 2014

Oxygenium 2014

Nitrogenium 2013

Carbo 2013

Boron 2013

Beryllium 2013

Lithium 2013

Helium 2013

Hydrogenium 2013

Omega 2013

Psi 2012

Chi 2012

Phi 2012

Upsilon 2012

Tau 2012

Sigma 2012

Rho 2012

Pi 2012

Omicron 2012

Xi 2012

Nu 2011

Mu 2011

Lambda 2011

Kappa 2011

Iota 2011

Theta 2011

Eta 2011

Zeta 2011

Epsilon 2011

Delta 2011

Gamma 2011

Beta 2010

Alpha 2010

ambitious

Given a string S, find the length of the longest balanced substring of S.

Programming language:
Spoken language:

A string is *balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

A *substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

Write a function `solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

2. Given S = "abababa", the function should return 6 ("ababab" and "bababa" are the longest balanced substrings).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

A string is *balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

A *substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

Write a function `solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

2. Given S = "abababa", the function should return 6 ("ababab" and "bababa" are the longest balanced substrings).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

A string is *balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

A *substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

Write a function `solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

2. Given S = "abababa", the function should return 6 ("ababab" and "bababa" are the longest balanced substrings).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

Write a function `Solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

*balanced* if it consists of exactly two different characters and both of those characters appear exactly the same number of times. For example: "aabbab" is balanced (both 'a' and 'b' occur three times) but "aabba" is not balanced ('a' occurs three times, 'b' occurs two times). String "aabbcc" is also not balanced (it contains three different letters).

*substring* of string S is a string that consists of consecutive letters in S. For example: "ompu" is a substring of "c** ompu**ter" but "cmptr" is not.

`solution` that, given a string S, returns the length of the longest balanced substring of S.

**Examples:**

1. Given S = "cabbacc", the function should return 4 ("abba" is the longest balanced substring).

3. Given S = "aaaaaaa", the function should return 0 (S does not contain a balanced substring).

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- string S consists only of lowercase letters (
a−z).

Information about upcoming challenges, solutions and lessons directly in your inbox.

© 2009–2018 Codility Ltd., registered in England and Wales (No. 7048726). VAT ID GB981191408. Registered office: 107 Cheapside, London EC2V 6DN