Minimum number of operations required to delete all elements of the array | Java implementation of the above approach ; function to find minimum operations ; sort array ; prepare hash of array ; Driver program
import java . util . * ; class Solution { static final int MAX = 10000 ; static int hashTable [ ] = new int [ MAX ] ; static int minOperations ( int arr [ ] , int n ) { Arrays . sort ( arr ) ; for ( int i = 0 ; i < n ; i ++ ) hashTable [ arr [ i ] ] ++ ; int res = 0 ; for ( int i = 0 ; i < n ; i ++ ) { if ( hashTable [ arr [ i ] ] != 0 ) { for ( int j = i ; j < n ; j ++ ) if ( arr [ j ] % arr [ i ] == 0 ) hashTable [ arr [ j ] ] = 0 ; res ++ ; } } return res ; } public static void main ( String args [ ] ) { int arr [ ] = { 4 , 6 , 2 , 8 , 7 , 21 , 24 , 49 , 44 } ; int n = arr . length ; System . out . print ( minOperations ( arr , n ) ) ; } }