Elements greater than the previous and next element in an Array
Given an array of N integers. The task is to print the elements from the array which are greater than their immediate previous and next elements.
Examples :
Input : arr[] = {2, 3, 1, 5, 4, 9, 8, 7, 5} Output : 3, 5, 9 In above given example 3 is greater than its left element 2 and right element 1. Similar logic is applied to other elements hence our final output is 3, 5, 9. Input : arr[] = {1, 2, 3, 2, 1} Output : 3
Approach: Since there is no element on the left of the first element(arr[0]) and there is no element to the right of last element(arr[N-1]) so these two elements will be excluded from the final answer.
Now, traverse the array starting from the index 1 to N-2 and for every element arr[i] check if arr[i] > arr[i-1] and arr[i] > arr[i+1].
Below is the implementation of the above approach:
C++
// C++ program to print elements greater than // the previous and next element in an Array #include <bits/stdc++.h> using namespace std; // Function to print elements greater than // the previous and next element in an Array void printElements( int arr[], int n) { // Traverse array from index 1 to n-2 // and check for the given condition for ( int i = 1; i < n - 1; i++) { if (arr[i] > arr[i - 1] and arr[i] > arr[i + 1]) cout << arr[i] << " " ; } } // Driver Code int main() { int arr[] = { 2, 3, 1, 5, 4, 9, 8, 7, 5 }; int n = sizeof (arr) / sizeof (arr[0]); printElements(arr, n); return 0; } |
Java
// Java program to print elements greater than // the previous and next element in an Array class GfG { // Function to print elements greater than // the previous and next element in an Array static void printElements( int arr[], int n) { // Traverse array from index 1 to n-2 // and check for the given condition for ( int i = 1 ; i < n - 1 ; i++) { if (arr[i] > arr[i - 1 ] && arr[i] > arr[i + 1 ]) System.out.print(arr[i] + " " ); } } // Driver Code public static void main(String[] args) { int arr[] = { 2 , 3 , 1 , 5 , 4 , 9 , 8 , 7 , 5 }; int n = arr.length; printElements(arr, n); } } // This code is contributed by Prerna Saini |
Python3
# Python 3 program to print elements greater than # the previous and next element in an Array # Function to print elements greater than # the previous and next element in an Array def printElements(arr, n): # Traverse array from index 1 to n-2 # and check for the given condition for i in range ( 1 , n - 1 , 1 ): if (arr[i] > arr[i - 1 ] and arr[i] > arr[i + 1 ]): print (arr[i], end = " " ) # Driver Code if __name__ = = '__main__' : arr = [ 2 , 3 , 1 , 5 , 4 , 9 , 8 , 7 , 5 ] n = len (arr) printElements(arr, n) # This code is contributed by # Surendra_Gangwar |
C#
using System; // c# program to print elements greater than // the previous and next element in an Array public class GfG { // Function to print elements greater than // the previous and next element in an Array public static void printElements( int [] arr, int n) { // Traverse array from index 1 to n-2 // and check for the given condition for ( int i = 1; i < n - 1; i++) { if (arr[i] > arr[i - 1] && arr[i] > arr[i + 1]) { Console.Write(arr[i] + " " ); } } } // Driver Code public static void Main( string [] args) { int [] arr = new int [] {2, 3, 1, 5, 4, 9, 8, 7, 5}; int n = arr.Length; printElements(arr, n); } } |
PHP
<?php // PHP program to print elements greater than // the previous and next element in an Array // Function to print elements greater than // the previous and next element in an Array function printElements( $arr , $n ) { // Traverse array from index 1 to n-2 // and check for the given condition for ( $i = 1; $i < $n - 1; $i ++) { if ( $arr [ $i ] > $arr [ $i - 1] and $arr [ $i ] > $arr [ $i + 1]) echo $arr [ $i ] . " " ; } } // Driver Code $arr = array (2, 3, 1, 5, 4, 9, 8, 7, 5); $n = sizeof( $arr ); printElements( $arr , $n ); // This code is contributed // by Akanksha Rai |
Javascript
<script> // Javascript implementation of the approach // Function to print elements greater than // the previous and next element in an Array function printElements(arr, n) { // Traverse array from index 1 to n-2 // and check for the given condition for ( var i = 1; i < n - 1; i++) { if (arr[i] > arr[i - 1] && arr[i] > arr[i + 1]) document.write( arr[i] + " " ); } } var arr = [ 2, 3, 1, 5, 4, 9, 8, 7, 5 ]; var n = arr.length; printElements(arr, n); // This code is contributed by SoumikMondal </script> |
Output:
3 5 9
Time Complexity : O(n)
Auxiliary Space : O(1)
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