# Maximum length subarray with difference between adjacent elements as either 0 or 1

• Difficulty Level : Easy
• Last Updated : 07 Dec, 2021

Given an array of n integers. The task is to find the maximum length of the sub-array such that absolute difference between all the consecutive elements of the sub-array is either 0 or 1.
Examples:

Input: arr[] = {2, 5, 6, 3, 7, 6, 5, 8}
Output:
{5, 6} and {7, 6, 5} are the only valid sub-arrays.
Input: arr[] = {-2, -1, 5, -1, 4, 0, 3}
Output:

Approach: Starting from the first element of the array, find the first valid sub-array and store it’s length then starting from the next element (the first element that wasn’t included in the first sub-array), find another valid sub-array. Repeat the process until all the valid sub-arrays have been found then print the length of the maximum sub-array.
Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach` `#include` `using` `namespace` `std;`   `// Function to return the maximum length` `// of the sub-array such that the` `// absolute difference between every two` `// consecutive elements is either 1 or 0` `int` `getMaxLength(``int` `arr[],``int` `n)` `{` `    ``int` `l = n;` `    ``int` `i = 0, maxlen = 0;` `    ``while` `(i < l)` `    ``{` `        ``int` `j = i;` `        ``while` `(i+1 < l &&` `             ``(``abs``(arr[i] - arr[i + 1]) == 1 ||` `             ``abs``(arr[i] - arr[i + 1]) == 0)) ` `        ``{` `            ``i++;` `        ``}`   `            ``// Length of the valid sub-array currently` `            ``// under consideration` `            ``int` `currLen = i - j + 1;`   `            ``// Update the maximum length` `            ``if` `(maxlen < currLen)` `                ``maxlen = currLen;`   `            ``if` `(j == i)` `                ``i++;` `    ``}`   `    ``// Any valid sub-array cannot be of length 1` `    ``//maxlen = (maxlen == 1) ? 0 : maxlen;`   `    ``// Return the maximum possible length` `    ``return` `maxlen;` `}`   `// Driver code` `int` `main()` `{` `    ``int` `arr[] = { 2, 4 };` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr);` `    ``cout << getMaxLength(arr, n);` `}`   `// This code is contributed by` `// Surendra_Gangwar`

## Java

 `// Java implementation of the approach` `public` `class` `GFG {`   `    ``// Function to return the maximum length` `    ``// of the sub-array such that the` `    ``// absolute difference between every two` `    ``// consecutive elements is either 1 or 0` `    ``public` `static` `int` `getMaxLength(``int` `arr[])` `    ``{`   `        ``int` `l = arr.length;` `        ``int` `i = ``0``, maxlen = ``0``;` `        ``while` `(i < l) {` `            ``int` `j = i;` `            ``while` `(i + ``1` `< l` `                   ``&& (Math.abs(arr[i] - arr[i + ``1``]) == ``1` `                       ``|| Math.abs(arr[i] - arr[i + ``1``]) == ``0``)) {` `                ``i++;` `            ``}`   `            ``// Length of the valid sub-array currently` `            ``// under cosideration` `            ``int` `currLen = i - j + ``1``;`   `            ``// Update the maximum length` `            ``if` `(maxlen < currLen)` `                ``maxlen = currLen;`   `            ``if` `(j == i)` `                ``i++;` `        ``}`   `        ``// Any valid sub-array cannot be of length 1` `        ``maxlen = (maxlen == ``1``) ? ``0` `: maxlen;`   `        ``// Return the maximum possible length` `        ``return` `maxlen;` `    ``}`   `    ``// Driver code` `    ``public` `static` `void` `main(String[] args)` `    ``{` `        ``int` `arr[] = { ``2``, ``4` `};` `        ``System.out.print(getMaxLength(arr));` `    ``}` `}`

## Python3

 `# Python3 implementation of the approach `   `# Function to return the maximum length ` `# of the sub-array such that the ` `# absolute difference between every two ` `# consecutive elements is either 1 or 0 ` `def` `getMaxLength(arr, n) :` `    `  `    ``l ``=` `n; ` `    ``i ``=` `0``; maxlen ``=` `0``;` `    `  `    ``while` `(i < l) :` `        ``j ``=` `i; ` `        ``while` `(i ``+` `1` `< l ``and` `              ``(``abs``(arr[i] ``-` `arr[i ``+` `1``]) ``=``=` `1` `or` `               ``abs``(arr[i] ``-` `arr[i ``+` `1``]) ``=``=` `0``)) :` `        `  `            ``i ``+``=` `1``; ` `        `  `        ``# Length of the valid sub-array ` `        ``# currently under cosideration ` `        ``currLen ``=` `i ``-` `j ``+` `1``; `   `        ``# Update the maximum length ` `        ``if` `(maxlen < currLen) : ` `            ``maxlen ``=` `currLen; `   `        ``if` `(j ``=``=` `i) :` `            ``i ``+``=` `1``; ` `    `  `    ``# Any valid sub-array cannot be of length 1 ` `    ``# maxlen = (maxlen == 1) ? 0 : maxlen; `   `    ``# Return the maximum possible length ` `    ``return` `maxlen; ` `    `  `# Driver code ` `if` `__name__ ``=``=` `"__main__"` `:`   `    ``arr ``=` `[ ``2``, ``4` `]; ` `    ``n ``=` `len``(arr) ` `    ``print``(getMaxLength(arr, n)); `   `# This code is contributed by Ryuga`

## C#

 `// C# implementation of the approach ` `using` `System;`   `class` `GFG ` `{ `   `    ``// Function to return the maximum length ` `    ``// of the sub-array such that the ` `    ``// Absolute difference between every two ` `    ``// consecutive elements is either 1 or 0 ` `    ``public` `static` `int` `getMaxLength(``int` `[]arr) ` `    ``{ `   `        ``int` `l = arr.Length; ` `        ``int` `i = 0, maxlen = 0; ` `        ``while` `(i < l) ` `        ``{ ` `            ``int` `j = i; ` `            ``while` `(i + 1 < l && ` `                    ``(Math.Abs(arr[i] - arr[i + 1]) == 1 ||` `                    ``Math.Abs(arr[i] - arr[i + 1]) == 0)) ` `            ``{ ` `                ``i++; ` `            ``} `   `            ``// Length of the valid sub-array currently ` `            ``// under consideration ` `            ``int` `currLen = i - j + 1; `   `            ``// Update the maximum length ` `            ``if` `(maxlen < currLen) ` `                ``maxlen = currLen; `   `            ``if` `(j == i) ` `                ``i++; ` `        ``} `   `        ``// Any valid sub-array cannot be of length 1 ` `        ``maxlen = (maxlen == 1) ? 0 : maxlen; `   `        ``// Return the maximum possible length ` `        ``return` `maxlen; ` `    ``} `   `    ``// Driver code ` `    ``public` `static` `void` `Main(String []args) ` `    ``{ ` `        ``int` `[]arr = { 2, 4 }; ` `        ``Console.Write(getMaxLength(arr)); ` `    ``} ` `} `   `// This code is contributed by Arnab Kundu`

## PHP

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## Javascript

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Output:

`1`

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