递归和非递归实现斐波那契序列


package com.edgar;

public class TestFibonacci {

public static void main(String[] args) {
// TODO Auto-generated method stub
long start1 = System.currentTimeMillis();
System.out.println(fibonacci(40));
long end1 = System.currentTimeMillis();
long start2 = System.currentTimeMillis();
System.out.println(fibonacci2(40));
long end2 = System.currentTimeMillis();

System.out.println(end1-start1);
System.out.println(end2-start2);
}

public static int fibonacci(int n){

if(n ==0){
return 0;
}
else if(n ==1 ||n==2){
return 1;
}
else{
return fibonacci(n-1)+ fibonacci(n-2);
}
}
// 1 1 2 3 5 8 13
// 1 2 3 4 5 6
public static int fibonacci2(int n){
if(n ==0){
return 0;
}
else if(n ==1 ||n==2){
return 1;
}
else{
int temp1 = 1;
int temp2 = 1;
int temp = 0;
for(int i=3;i<=n;i++){
temp = temp1+ temp2;
temp2 = temp1;
temp1 = temp;
}

return temp;
}
}

}

你可能感兴趣的:(java,java)