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: 3
{5, 6} and {7, 6, 5} are the only valid sub-arrays.
Input: arr[] = {-2, -1, 5, -1, 4, 0, 3}
Output: 2
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<bits/stdc++.h> 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[0]); 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
<?php // PHP 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 function getMaxLength( $arr , $n ) { $l = $n ; $i = 0; $maxlen = 0; while ( $i < $l ) { $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 $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 $arr = array (2, 4 ); $n = sizeof( $arr ); echo getMaxLength( $arr , $n ) // This code is contributed by ita_c ?> |
Javascript
<script> // Javascript 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 function getMaxLength(arr) { let l = arr.length; let i = 0, maxlen = 0; while (i < l) { let 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 let 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 let arr = [2, 4 ]; document.write(getMaxLength(arr)); // This code is contributed by rag2127. </script> |
1
Time Complexity : O(n) ,where n is size of given array.
Space Complexity : O(1) ,as we are not using any extra space.
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