Sum of range in a series of first odd then even natural numbers | Java program to find sum in the given range in the sequence 1 3 5 7. ... . N 2 4 6. . . N - 1 ; Function that returns sum in the range 1 to x in the sequence 1 3 5 7. ... . N 2 4 6. . . N - 1 ; number of odd numbers ; number of extra even numbers required ; Driver Code
class GFG { static double sumTillX ( double x , double n ) { double odd = Math . ceil ( n / 2.0 ) ; if ( x <= odd ) return x * x ; double even = x - odd ; return ( ( odd * odd ) + ( even * even ) + even ) ; } static double rangeSum ( double N , double L , double R ) { return sumTillX ( R , N ) - sumTillX ( L - 1 , N ) ; } public static void main ( String args [ ] ) { long N = 10 , L = 1 , R = 6 ; int n = 101 ; System . out . println ( ( int ) rangeSum ( N , L , R ) ) ; } }