Number of Co | Java program to count the pairs whose sum of digits is co - prime ; Function to find the elements after doing the sum of digits ; Traverse from a to b ; Find the sum of the digits of the elements in the given range one by one ; Function to count the co - prime pairs ; Function to make the pairs by doing the sum of digits ; Count pairs that are co - primes ; Driver code ; Function to count the pairs
import java . util . * ; class GFG { static int GCD ( int a , int b ) { if ( b == 0 ) return a ; return GCD ( b , a % b ) ; } static void makePairs ( Vector < Integer > pairs , int a , int b ) { for ( int i = a ; i <= b ; i ++ ) { int sumOfDigits = 0 , k = i ; while ( k > 0 ) { sumOfDigits += k % 10 ; k /= 10 ; } if ( sumOfDigits <= 162 ) pairs . add ( sumOfDigits ) ; } } static int countCoPrime ( int a , int b ) { Vector < Integer > pairs = new Vector < Integer > ( ) ; makePairs ( pairs , a , b ) ; int count = 0 ; for ( int i = 0 ; i < pairs . size ( ) ; i ++ ) for ( int j = i + 1 ; j < pairs . size ( ) ; j ++ ) if ( GCD ( pairs . get ( i ) , pairs . get ( j ) ) == 1 ) count ++ ; return count ; } public static void main ( String args [ ] ) { int a = 12 , b = 15 ; System . out . println ( countCoPrime ( a , b ) ) ; } }