Find element in array that divides all array elements
Given an array of n non-negative integers. Find such element in the array, that all array elements are divisible by it.
Examples :
Input : arr[] = {2, 2, 4}
Output : 2
Input : arr[] = {2, 1, 3, 1, 6}
Output : 1
Input: arr[] = {2, 3, 5}
Output : -1
The approach is to calculate GCD of the entire array and then check if there exist an element equal to the GCD of the array. For calculating the gcd of the entire array we will use Euclidean algorithm.
C++
// CPP program to find such number in the array // that all array elements are divisible by it #include <bits/stdc++.h> using namespace std; // Returns gcd of two numbers. int gcd(int a, int b) { if (a == 0) return b; return gcd(b % a, a); } // Function to return the // desired number if exists int findNumber(int arr[], int n) { // Find GCD of array int ans = arr[0]; for (int i = 0; i < n; i++) ans = gcd(ans, arr[i]); // Check if GCD is present in array for (int i = 0; i < n; i++) if (arr[i] == ans) return ans; return -1; } // Driver Function int main() { int arr[] = { 2, 2, 4 }; int n = sizeof(arr) / sizeof(arr[0]); cout << findNumber(arr, n) << endl; return 0; } |
chevron_right
filter_none
Java
// JAVA program to find such number in // the array that all array elements // are divisible by it import java.io.*; class GFG { // Returns GCD of two numbers static int gcd(int a, int b) { if (a == 0) return b; return gcd(b % a, a); } // Function to return the desired // number if exists static int findNumber(int arr[], int n) { // Find GCD of array int ans = arr[0]; for (int i = 0; i < n; i++) ans = gcd(ans, arr[i]); // Check if GCD is present in array for (int i = 0; i < n; i++) if (arr[i] == ans) return ans; return -1; } // Driver Code public static void main(String args[]) { int arr[] = { 2, 2, 4 }; int n = arr.length; System.out.println(findNumber(arr, n)); } } // This code is contributed by Nikita Tiwari |
chevron_right
filter_none
Python3
# Python3 program to find such number # in the array that all array # elements are divisible by it # Returns GCD of two numbers def gcd (a, b) : if (a == 0) : return b return gcd (b % a, a) # Function to return the desired # number if exists def findNumber (arr, n) : # Find GCD of array ans = arr[0] for i in range(0, n) : ans = gcd (ans, arr[i]) # Check if GCD is present in array for i in range(0, n) : if (arr[i] == ans) : return ans return -1 # Driver Code arr = [2, 2, 4]; n = len(arr) print(findNumber(arr, n)) # This code is contributed by Nikita Tiwari |
chevron_right
filter_none
C#
// C# program to find such number in // the array that all array elements // are divisible by it using System; class GFG { // Returns GCD of two numbers static int gcd(int a, int b) { if (a == 0) return b; return gcd(b % a, a); } // Function to return the desired // number if exists static int findNumber(int[] arr, int n) { // Find GCD of array int ans = arr[0]; for (int i = 0; i < n; i++) ans = gcd(ans, arr[i]); // Check if GCD is present in array for (int i = 0; i < n; i++) if (arr[i] == ans) return ans; return -1; } // Driver Code public static void Main() { int[] arr = { 2, 2, 4 }; int n = arr.Length; Console.WriteLine(findNumber(arr, n)); } } // This code is contributed by vt_m |
chevron_right
filter_none
PHP
<?php // PHP program to find such // number in the array that // all array elements are // divisible by it // Returns gcd of two numbers function gcd ($a, $b) { if ($a == 0) return $b; return gcd ($b % $a, $a); } // Function to return the // desired number if exists function findNumber ($arr, $n) { // Find GCD of array $ans = $arr[0]; for ($i = 0; $i < $n; $i++) $ans = gcd ($ans, $arr[$i]); // Check if GCD is // present in array for ($i = 0; $i < $n; $i++) if ($arr[$i] == $ans) return $ans; return -1; } // Driver Code $arr =array (2, 2, 4); $n = sizeof($arr); echo findNumber($arr, $n), "\n"; // This code is contributed by ajit ?> |
chevron_right
filter_none
Output :
2
Recommended Posts:
- Find an element which divides the array in two subarrays with equal product
- Find a number that divides maximum array elements
- Find integers that divides maximum number of elements of the array
- Smallest integer > 1 which divides every element of the given array
- Find an array element such that all elements are divisible by it
- Find the element having different frequency than other array elements
- Find an element in an array such that elements form a strictly decreasing and increasing sequence
- Find an element in array such that sum of left array is equal to sum of right array
- Find original array from encrypted array (An array of sums of other elements)
- For each element in 1st array count elements less than or equal to it in 2nd array | Set 2
- Construct an array from XOR of all elements of array except element at same index
- For each element in 1st array count elements less than or equal to it in 2nd array
- Divide every element of one array by other array elements
- Elements of an array that are not divisible by any element of another array
- Find minimum value to assign all array elements so that array product becomes greater
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.
- Sum of digits with even number of 1's in their binary representation
- Pair with largest sum which is less than K in the array
- Find the smallest positive number missing from an unsorted array | Set 3
- Reduce number to a single digit by subtracting adjacent digits repeatedly
- Sort an array of strings according to string lengths using Map
