编程算法 - 阶乘和Fibonacci数列(递归)

阶乘和Fibonacci数列(递归)

本文地址: http://blog.csdn.net/caroline_wendy

递归的基础, 实现阶乘和Fibonacci数列, fib数列可以通过动态规划, 减少计算次数.
代码:
/*
* main.cpp
*
* Created on: 2014.7.13
* Author: Spike
*/

/*eclipse cdt, gcc 4.8.1*/

#include <stdio.h>

using namespace std;

int fact(int n) {
if (n==0)
return 1;
return n*fact(n-1);
}

int fib(int n) {
if (n<=1) return n;
return fib(n-1)+fib(n-2);
}

int fib_memo(int* memo, int n) {
if (n<=1) return n;
if (memo
!=0) return memo
;
return memo
= fib(n-1)+fib(n-2);
}

int main(void)
{
int result_fib = fib(6);
printf("result_fib = %d\n", result_fib);

const int MAX_N = 20;
int memo[MAX_N+1];
for (int i; i<MAX_N+1; ++i)
memo[i] = 0;

int result_fib_memo = fib_memo(memo, 6);
printf("result_fib_memo = %d\n", result_fib_memo);

return 0;
}


输出:
result_fib = 8
result_fib_memo = 8

Java代码:
//: Main.java

/**
* Fibonacci数列
*/
class Main {

public static int fib(int n) {
if (n<=1) return n;
return fib(n-1)+fib(n-2);
}

public static void main(String[] args) {
String result = "";
int num = Integer.valueOf(args[0]);
if (num <= 0) System.out.println("数字异常");
for (int i=1; i<=num; ++i) {
result += fib(i) + " ";
}
System.out.println(result);
}
}
/**
* Output:
* 1 1 2 3 5
*///:~