牛客网-斐波那契数列

public class Solution {
    public int Fibonacci(int n) {
        
        if(n == 0)
            return 0;
        
        int a=1;
        int b=1;
        int c=1;
        
        while(n>2){
            
            c = a + b;
            a=b;
            b=c;
            
            n--;
        }
        
        return c;
        
    }
}

public class Solution {
    public int Fibonacci(int n) {
        if(n==0)
            return 0;
        
        if(n<=2)
            return 1;
        
        return Fibonacci(n-1) + Fibonacci(n - 2);
    }
}