Sum of multiples of A and B less than N | Java program to find the sum of all multiples of A and B below N ; Function to find sum of AP series ; Number of terms ; Function to find the sum of all multiples of A and B below N ; Since , we need the sum of multiples less than N ; common factors of A and B ; Driver code
class GFG { static int __gcd ( int a , int b ) { if ( b == 0 ) return a ; return __gcd ( b , a % b ) ; } static int sumAP ( int n , int d ) { n /= d ; return ( n ) * ( 1 + n ) * d / 2 ; } static int sumMultiples ( int A , int B , int n ) { n -- ; int common = ( A * B ) / __gcd ( A , B ) ; return sumAP ( n , A ) + sumAP ( n , B ) - sumAP ( n , common ) ; } public static void main ( String [ ] args ) { int n = 100 , A = 5 , B = 10 ; System . out . println ( " Sum ▁ = ▁ " + sumMultiples ( A , B , n ) ) ; } }