题目描述
大家都知道斐波那契数列,现在要求输入一个整数n,请你输出斐波那契数列的第n项(从0开始,第0项为0)。(n<=39)
法一:
public class Solution { public int Fibonacci(int n) { int[] fib = new int[40]; fib[0] = 0; fib[1] = 1; for(int i = 2; i < 40; i++) fib[i] = fib[i-1] + fib[i-2]; return fib[n]; } }
法二:
public class Solution { public int Fibonacci(int n) { if(n == 0 || n == 1) return n; int fn1 = 0; int fn2 = 1; for(int i=2; i<=n; i++){ fn2 += fn1; fn1 = fn2 - fn1; } return fn2; } }