7. 斐波那契数列

/*斐波那契数列*/
/*输入一个整数n，输出斐波那契数列的第n项。n<=39*/

class Solution {
public:
    int Fibonacci(int n) {
        int result[2] = {0, 1};
        if(n < 2)
            return result[n];
        int Fibone = 0;
        int Fibtwo = 1;
        int FibN = 0;
        for(int i = 2; i <= n; ++ i){
            FibN = Fibone + Fibtwo;
            Fibone = Fibtwo;
            Fibtwo = FibN;
        }
        return FibN;
    }
};