Recursive program to linearly search an element in a given array
Given an unsorted array and an element x, search x in given array. Write recursive C code for this. If element is not present, return -1.
Approach : The idea is to compare x with first element in arr[]. If element is found at first position, return it. Else recur for remaining array and x.
C++
// Recursive C++ program // to search x in array #include<bits/stdc++.h> using namespace std; // Recursive function to // search x in arr[l..r] int recSearch(int arr[], int l, int r, int x) { if (r < l) return -1; if (arr[l] == x) return l; if (arr[r] == x) return r; return recSearch(arr, l + 1, r - 1, x); } // Driver Code int main() { int arr[] = {12, 34, 54, 2, 3}, i; int n = sizeof(arr) / sizeof(arr[0]); int x = 3; int index = recSearch(arr, 0, n - 1, x); if (index != -1) cout << "Element " << x << " is present at index " << index; else cout << "Element" << x << " is not present" ; return 0; } // This code is contributed // by Shivi_Aggarwal |
C
#include<stdio.h> /* Recursive function to search x in arr[l..r] */int recSearch(int arr[], int l, int r, int x) { if (r < l) return -1; if (arr[l] == x) return l; if (arr[r] == x) return r; return recSearch(arr, l+1, r-1, x); } int main() { int arr[] = {12, 34, 54, 2, 3}, i; int n = sizeof(arr)/sizeof(arr[0]); int x = 3; int index = recSearch(arr, 0, n-1, x); if (index != -1) printf("Element %d is present at index %d", x, index); else printf("Element %d is not present", x); return 0; } |
Java
// Recursive Java program to search x in array class Test { static int arr[] = {12, 34, 54, 2, 3}; /* Recursive Method to search x in arr[l..r] */ static int recSearch(int arr[], int l, int r, int x) { if (r < l) return -1; if (arr[l] == x) return l; if (arr[r] == x) return r; return recSearch(arr, l+1, r-1, x); } // Driver method public static void main(String[] args) { int x = 3; //Method call to find x int index = recSearch(arr, 0, arr.length-1, x); if (index != -1) System.out.println("Element " + x + " is present at index " + index); else System.out.println("Element " + x + " is not present"); } } |
Python
# Recursive function to search x in arr[l..r] def recSearch( arr, l, r, x): if r < l: return -1 if arr[l] == x: return l if arr[r] == x: return r return recSearch(arr, l+1, r-1, x) # Driver Code arr = [12, 34, 54, 2, 3] n = len(arr) x = 3index = recSearch(arr, 0, n-1, x) if index != -1: print "Element", x,"is present at index %d" %(index) else: print "Element %d is not present" %(x) # Contributed By Harshit Agrawal |
C#
// Recursive C# program to // search x in array using System; static class Test { static int []arr = {12, 34, 54, 2, 3}; /* Recursive Method to search x in arr[l..r] */ static int recSearch(int []arr, int l, int r, int x) { if (r < l) return -1; if (arr[l] == x) return l; if (arr[r] == x) return r; return recSearch(arr, l+1, r-1, x); } // Driver method public static void Main(String[] args) { int x = 3; // Method call to find x int index = recSearch(arr, 0, arr.Length-1, x); if (index != -1) Console.Write("Element " + x + " is present at index " + index); else Console.Write("Element " + x + " is not present"); } } // This code is contributed by Smitha Dinesh Semwal |
PHP
<?php // Recursive PHP program to // search x in array // Recursive function to // search x in arr[l..r] function recSearch($arr, int $l, int $r, int $x) { if ($r < $l) return -1; if ($arr[$l] == $x) return $l; if ($arr[$r] == $x) return $r; return recSearch($arr, $l+1, $r-1, $x); } // Driver Code $arr = array(12, 34, 54, 2, 3); $i; $n = count($arr); $x = 3; $index = recSearch($arr, 0, $n - 1, $x); if ($index != -1) echo "Element"," ", $x," ", "is present at index ", $index; else echo "Element is not present", $x; // This code is contributed by anuj_67. ?> |
Output:
Element 3 is present at index 4
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