Finding LCM of more than two ( or array ) numbers without using GCD | C # program to find LCM of array without using GCD . ; Returns LCM of arr [ 0. . n - 1 ] ; Find the maximum value in arr [ ] ; Initialize result ; Find all factors that are present in two or more array elements . int x = 2 ; Current factor . ; To store indexes of all array elements that are divisible by x . ; If there are 2 or more array elements that are divisible by x . ; Reduce all array elements divisible by x . ; Then multiply all reduced array elements ; Driver code
using System ; using System . Collections ; class GFG { static long LCM ( int [ ] arr , int n ) { int max_num = 0 ; for ( int i = 0 ; i < n ; i ++ ) { if ( max_num < arr [ i ] ) { max_num = arr [ i ] ; } } long res = 1 ; while ( x <= max_num ) { ArrayList indexes = new ArrayList ( ) ; for ( int j = 0 ; j < n ; j ++ ) { if ( arr [ j ] % x == 0 ) { indexes . Add ( j ) ; } } if ( indexes . Count >= 2 ) { for ( int j = 0 ; j < indexes . Count ; j ++ ) { arr [ ( int ) indexes [ j ] ] = arr [ ( int ) indexes [ j ] ] / x ; } res = res * x ; } else { x ++ ; } } for ( int i = 0 ; i < n ; i ++ ) { res = res * arr [ i ] ; } return res ; } public static void Main ( ) { int [ ] arr = { 1 , 2 , 3 , 4 , 5 , 10 , 20 , 35 } ; int n = arr . Length ; Console . WriteLine ( LCM ( arr , n ) ) ; } }