标签：class blog code java com string
求平方和
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30 |
public static void main(String[] args) throws
IOException { int
n; String s; BufferedReader buf; buf=new
BufferedReader(new
InputStreamReader(System.in)); System.out.print("请输入一个自然数："); s=buf.readLine(); n=Integer.parseInt(s); System.out.print("f(n)=1"); for(int
i=2;i<=n;i++) System.out.print("+"+i*i); System.out.print("="+Square(n)); } public
static long Square(int
n) { long
f=0; if(n<0) System.out.println("n<0，输入错误！"); else
if (n==1)f=1; else f=Square(n-1)+n*n; return
f; } |
穷举质数
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 |
public static void main(String args[]) { int
i,j; for(j=2;;j++) { for(i=2;i<=j/2;i++) { if(j%i==0) break; } if(i>j/2) { System.out.println(j); } } } |
求质因子
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51 |
public static void main(String[] args) { int
n = 0; String s = null; BufferedReader buf; buf=new
BufferedReader(new
InputStreamReader(System.in)); System.out.print("请输入一个数："); try
{ s=buf.readLine(); } catch
(IOException e) { e.printStackTrace(); } n=Integer.parseInt(s); int
temp = n; for
(int i = 2; i <= temp; i++) { if
(!isPrime(i)) { continue; } while
(true) { if
(temp%i == 0) { temp = temp/i; System.out.println(i); } else
{ break; } } } } public
static boolean isPrime(int
n) { int
i; for
(i = 2; i <= n; i++) { if
(n%i == 0) { break; } } if
(i >= n) { return
true; } else
{ return
false; } } |
Java小例子——穷举质数，求平方和，求质因子。,布布扣,bubuko.com
标签：class blog code java com string
原文地址：http://www.cnblogs.com/zmrid/p/3773012.html
