fibonacci数列的题目——剑指Offer

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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。

n<=39

class Solution {
public:int Fibonacci(int n) {if (n < 1) return 0;if (n <= 2) return 1;int fib2 = 1;int fib1 = 1;for (int i=3; i<=n; i++) {int tmp = fib2 + fib1;fib2 = fib1;fib1 = tmp;}return fib1;}
};