how to check if a given number is fibonacci number? in python code example
Example: Python Program for How to check if a given number is Fibonacci number?
# python program to check if x is a perfect square
import math
# A utility function that returns true if x is perfect square
def isPerfectSquare(x):
s = int(math.sqrt(x))
return s*s == x
# Returns true if n is a Fibinacci Number, else false
def isFibonacci(n):
# n is Fibinacci if one of 5*n*n + 4 or 5*n*n - 4 or both
# is a perferct square
return isPerfectSquare(5*n*n + 4) or isPerfectSquare(5*n*n - 4)
# A utility function to test above functions
for i in range(1,11):
if (isFibonacci(i) == True):
print i,"is a Fibonacci Number"
else:
print i,"is a not Fibonacci Number "