java-斐波那契数列的解法

public class Feibo {
	
	static long[] temp = new long[1000000];
	
	static long fun1(int n){
		if(temp[n]!=0)
			return temp[n];
		if(n==1||n==2)
			return temp[1]=temp[2]=1;
		return temp[n]=fun1(n-2)+fun1(n-1);
	}
	
	static long fun2(int n){
		if(n==1||n==2)
			return 1;
		return fun2(n-2)+fun2(n-1);
	}
	
	//尾递归
	//fun2(1,0,5);
	static long fun2(long a,long b,int n){
		if(n==1)
			return a;
		return fun2(a+b,a,n-1);
	}
}