题目地址

    思路一：

    1. public int Fibonacci(int n) {
    2.     int a = 0, b = 1;
    3.     if (n == 0) {
    4.         return a;
    5.     } 
    6.     else if (n == 1) {
    7.         return b;
    8.     } else {
    9.         int temp;
    10.         for (int i = 0; i <= n - 2; i++) {
    11.             temp = b;
    12.             b = a + b;
    13.             a = temp;
    14.         }
    15.         return b;
    16.     }
    17. }