LintCode-366. 斐波纳契数列

class Solution {
    /**
     * @param n: an integer
     * @return an integer f(n)
     */
    public int fibonacci(int n) {
        // write your code here
        if(n < 3) return n-1;
        // else return fibonacci(n-1) + fibonacci(n-2);
        else{
            int a = 0, b =1, c = 0;
            for (int i = 0; i < n - 2; i++ ){
                c = a + b;
                a = b;
                b = c;
            }
            return c;
        }
    }
}

class Solution {
    /**
     * @param n: an integer
     * @return an integer f(n)
     */
    public int fibonacci(int n) {
        // write your code here
        if(n < 3) return n-1;
        else return fibonacci(n-1) + fibonacci(n-2);
        }
    }
}