Find the sum of the ascii values of characters which are present at prime positions | Java implementation of the approach ; Function that returns true if n is prime ; Function to return the sum of the ascii values of the characters which are present at prime positions ; To store the sum ; For every character ; If current position is prime then add the ASCII value of the character at the current position ; Driver code
import java . util . * ; class GFG { static boolean isPrime ( int n ) { if ( n == 0 n == 1 ) { return false ; } for ( int i = 2 ; i * i <= n ; i ++ ) { if ( n % i == 0 ) { return false ; } } return true ; } static int sumAscii ( String str , int n ) { int sum = 0 ; for ( int i = 0 ; i < n ; i ++ ) { if ( isPrime ( i + 1 ) ) { sum += ( int ) ( str . charAt ( i ) ) ; } } return sum ; } public static void main ( String [ ] args ) { String str = " geeksforgeeks " ; int n = str . length ( ) ; System . out . println ( sumAscii ( str , n ) ) ; } }