leetcode-1414 Find the Minimum Number of Fibonacci Numbers Whose Sum Is K

Given an integer k, return the minimum number of Fibonacci numbers whose sum is equal to k. The same Fibonacci number can be used multiple times.

The Fibonacci numbers are defined as:

F1 = 1
F2 = 1
Fn = Fn-1 + Fn-2 for n > 2.
It is guaranteed that for the given constraints we can always find such Fibonacci numbers that sum up to k.

输入输出实例：

Input: k = 7
Output: 2 
Explanation: The Fibonacci numbers are: 1, 1, 2, 3, 5, 8, 13, ... 
For k = 7 we can use 2 + 5 = 7.

代码：

class Solution:
    def findMinFibonacciNumbers(self, k: int) -> int:
        F1, F2 = 1, 1
        while F2 <= k:
            F2, F1 = F2 + F1, F2
        num = 0
        while F1 > 0:
            if k > F2:
                num += 1
                k -= F2
            F2, F1 = F1, F2 - F1
        return num