text: // Problem :    https://leetcode.com/problems/sqrtx/
  // Solution:    https://github.com/tjzhym/LeetCode-solution
  // Author :     zhym (tjzhym)
  // Date   :     2021-8-12
  
  
  class Solution {
  public:
      int climbStairs(int n) {
          int fibonacciNumber = 1, firstNumber = 0, secondNumber = 0;
          for (int fibonacciIndex = 0; fibonacciIndex < n; ++fibonacciIndex) {
              firstNumber = secondNumber;
              secondNumber = fibonacciNumber;
              fibonacciNumber = firstNumber + secondNumber;
  
          }
          return fibonacciNumber;
      }
  };
  
  // Dynamic Programming