- 斐波那契数列每次只需要用到两个数据,计算后也只需要保存两个数据(向前覆盖)
public class Solution { public int Fibonacci(int n) { // 排除前两项 if(n < 2) { return n; } // 保存前两项计算该项 int first = 0, second = 1; for(int i = 2; i <= n; i++) { second = first + second; first = second - first; } return second; } }