编程作业（2） - 编程题 5. 密码检查(JAVA)

import java.util.Scanner;
public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    while (s.hasNext()) {
      String str = s.next();
      if (str.length() < 8) {
        System.out.println("NG");
        continue;
      }
      char[] chars = str.toCharArray();
      int a=0,b = 0,c=0,d=0;
      for (int i = 0; i < str.length(); i++) {
        if (Character.isDigit(chars[i])) a=1;
        else if (Character.isUpperCase(chars[i])) b=1;
        else if (Character.isLowerCase(chars[i])) c=1;
        else d=1;
      }
      if (a+b+c+d<3) {
        System.out.println("NG") ;
        continue;
      }
      boolean flag=true;
      for (int i = 0; i <= str.length()-2; i++) {
        for (int j = i + 2; j <= str.length(); j++) {
          String substring = str.substring(i, j);
//          System.out.println(substring+" "+str.indexOf(substring));
          if (str.indexOf(substring)!=i&&(j-str.indexOf(substring))>=(substring.length()*2)) {
            flag=false;
          } 
        }
      }
      if(flag){
        System.out.println("OK");
      }else{
        System.out.println("NG");
      }
    }
  }
}