Non Fibonacci Numbers | Java program to find n 'th Fibonacci number ; Returns n 'th Non-  Fibonacci number ; curr is to keep track of current fibonacci number , prev is previous , prevPrev is previous of previous . ; While count of non - fibonacci numbers doesn 't become  negative or zero ; Simple Fibonacci number logic ; ( curr - prev - 1 ) is count of non - Fibonacci numbers between curr and prev . ; n might be negative now . Make sure it becomes positive by removing last added gap . ; Now add the positive n to previous Fibonacci number to find the n 'th non-fibonacci. ; Driver Code
import java . io . * ; class GFG { static int nonFibonacci ( int n ) { int prevPrev = 1 , prev = 2 , curr = 3 ; while ( n > 0 ) { prevPrev = prev ; prev = curr ; curr = prevPrev + prev ; n = n - ( curr - prev - 1 ) ; } n = n + ( curr - prev - 1 ) ; return prev + n ; } public static void main ( String args [ ] ) { System . out . println ( nonFibonacci ( 5 ) ) ; } }