题解 | #斐波那契数列# [P0]

public class Solution {
    public int Fibonacci(int n) {
      if (n <= 2) return 1;
      int f_a = 1;
      int f_b = 1;
      
      for (int i = 3; i<=n; ++i) {
        int tmp = f_a + f_b;
        f_a = f_b;
        f_b = tmp;
      }
      
      return f_b;
    }
}