Number of trees whose sum of degrees of all the vertices is L | Iterative Function to calculate ( x ^ y ) in O ( log y ) ; Initialize result ; If y is odd , multiply x with result ; y must be even now y = y / 2 ; Function to return the count of required trees ; number of nodes ; Return the result ; Driver code
function power ( x , y ) { var res = 1 ; while ( y > 0 ) { if ( y & 1 ) res = ( res * x ) ; y = y >> 1 ; x = ( x * x ) ; } return res ; } function solve ( L ) { var n = L / 2 + 1 ; var ans = power ( n , n - 2 ) ; return ans ; } var L = 6 ; document . write ( solve ( L ) ) ;