剑指offer系列之7：斐波那契数列

public static int fibonacci(int n) {
if (n == 1 || n == 2) {
return 1;
} else {
return fibonacci(n - 1) + fibonacci(n - 2);
}
}

public class Solution {
public int Fibonacci(int n) {
int x,y,z;
if(n==0 || n==1)
return n;
else{
x=0;
y=1;
for(int i = 2;i <= n;i++){
z = y;
y = x+y;
x = z;
}
}
return y;
}
}