Calculate the Sum of GCD over all subarrays | Java program to find Sum of GCD over all subarrays . ; Utility function to calculate sum of gcd of all sub - arrays . ; Fixing the starting index of a subarray ; Fixing the ending index of a subarray ; Finding the GCD of this subarray ; Adding this GCD in our sum ; Driver Code
class GFG { static int findGCDSum ( int n , int a [ ] ) { int GCDSum = 0 ; int tempGCD = 0 ; for ( int i = 0 ; i < n ; i ++ ) { for ( int j = i ; j < n ; j ++ ) { tempGCD = 0 ; for ( int k = i ; k <= j ; k ++ ) { tempGCD = __gcd ( tempGCD , a [ k ] ) ; } GCDSum += tempGCD ; } } return GCDSum ; } static int __gcd ( int a , int b ) { return b == 0 ? a : __gcd ( b , a % b ) ; } public static void main ( String [ ] args ) { int n = 5 ; int a [ ] = { 1 , 2 , 3 , 4 , 5 } ; int totalSum = findGCDSum ( n , a ) ; System . out . print ( totalSum + "NEW_LINE"); } }