Posted on 2010-05-22 13:40
java小爬蟲 閱讀(3354)
評論(2) 編輯 收藏
今天參加了一場java筆試，考了斐波那契
數列。以前也見過考階乘的。今天順手把它寫下來。
public class Recursion {
public static long factorial(int i) {
if (i < 0)
return -1;
else if (i == 0 || i == 1)
return 1;
else
return i * factorial(i - 1);
}
public static int sum(int i) {
if (i == 0)
return 0;
else
return i + sum(i - 1);
}
public static int fibonacci(int i) {
if (i == 0 || i == 1)
return 1;
else
return fibonacci(i - 1) + fibonacci(i - 2);
}
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
System.out.println(i + "!= " + factorial(i));
System.out.println("sum(" + i + "!) = " + sum(i));
System.out.println("fibonacci(" + i + ")= " + fibonacci(i));
System.out.println("=========================");
}
}
}