Find number from its divisors | Java implementation of the approach ; Function that returns X ; Sort the given array ; Get the possible X ; Container to store divisors ; Find the divisors of x ; Check if divisor ; sort the vec because a is sorted and we have to compare all the elements ; if size of both vectors is not same then we are sure that both vectors can 't be equal ; Check if a and vec have same elements in them ; Driver code ; Function call
import java . util . * ; class GFG { static int findX ( int a [ ] , int n ) { Arrays . sort ( a ) ; int x = a [ 0 ] * a [ n - 1 ] ; Vector < Integer > vec = new Vector < Integer > ( ) ; for ( int i = 2 ; i * i <= x ; i ++ ) { if ( x % i == 0 ) { vec . add ( i ) ; if ( ( x / i ) != i ) vec . add ( x / i ) ; } } Collections . sort ( vec ) ; if ( vec . size ( ) != n ) return - 1 ; else { int i = 0 ; for ( int it : vec ) { if ( a [ i ++ ] != it ) return - 1 ; } } return x ; } public static void main ( String [ ] args ) { int a [ ] = { 2 , 5 , 4 , 10 } ; int n = a . length ; System . out . print ( findX ( a , n ) ) ; } }