public class Fibonacci {
public static int fibo1(int n){ //递归算法
if(n==1||n==2){
return 1;
}
else{
return fibo1(n-1)+fibo1(n-2);
}
}
public static int fibo2(int n){ //数学表达式算法Fib(n) = [(1+√5)/2]^n /√5 - [(1-√5)/2]^n /√5
return (int) ((Math.pow((1+Math.sqrt(5.0))/2,n)-Math.pow((1-Math.sqrt(5.0))/2,n))/Math.sqrt(5.0));
}
public static int fibo3(int n){ //循环函数算法
int a=1,b=1,c=0;
for(int i=2;i c=a+b;
a=b;
b=c;
}
return c;
}
public static int fibo4(int n){//循环向量函数算法
int fi=0;
int[] fib = new int[n];
fib[0] = 1;
fib[1] = 1;
for(int i = 2; i < fib.length; i++){
fib[i] = fib[i-1] + fib[i-2];
fi=fib[i];
}
return fi;
}
public static void main(String[] args) {
System.out.println(fibo1(10));
System.out.println(fibo2(10));
System.out.println(fibo3(10));
System.out.println(fibo4(10));
}
}