Question

java如何实现a-z,0-9组成3个字符密码,将可能密码组合全部打印出

Answer 1

以前写着玩的，用于枚举登录密码的。。。
public class Test2 {
private final static String bk = "0123456789abcdefghijklmnopqrstuvwxyz";
public static void main(String[] args) {
String cur = "zz";
while((cur = getNext(cur)).length() < 4) {
System.out.println(cur);
}
}

private static String getNext(String cur) {

if(cur.length() == 0)
return bk.charAt(0) + "";

int len = bk.length();

String ret = "";
char[] cs = cur.toCharArray();
for(int i = cs.length - 1; i > -1; i--) {

int p = bk.indexOf(cs[i] + "");
if(p == len - 1) {
ret += bk.charAt(0);
if(i == 0) {
return bk.charAt(0) + ret;
}
} else {
ret = cur.substring(0, i) + bk.charAt(p + 1) + ret;
return ret;
}
}

return ret;
}
}

Answer 2

当我看完这个问题时，我脑海中闪现了三重循环！！！