CodeGym/Help with Java Tasks/last condition not verifying

Level 31

Clearwater

30.10.2020
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9comments

last condition not verifying

Question about the task

Resolved

I have tried with multiple test inputs and seem to get the correct result. any help would be greatly appreciated. thank you.

The main method's first argument is a string that contains a sequence of characters (All characters in the string have ASCII codes (32 to 127 inclusive)). The string length does not exceed 255 characters. You need to implement a program that determines whether the content of the string is a number written in a number system whose base does not exceed 36. If it is, then you need to display the smallest valid radix for this number. If it is not, then you need to display "Invalid".
Number systems whose base is greater than 10 use Latin letters as numerals. For example, the number 35 in the decimal system corresponds to the number "Z" in the system with a base of 36. Since we are considering positional notation, the minimum base that the program should display is 2.
If any exceptions occur, catch them and do not display the stack trace.

Example 1:
Input:

Expected output:

Example 2:
Input:

12AS08z

Expected output:

Example 3:
Input:

12AS08Z/

Expected output:

Invalid

Requirements:

If any exception has occurred, you need to catch it and not display the stack trace.
If the input string contains anything other than Latin letters and numbers, you must display "Invalid".
If the input string is valid, you need to display the base of the number system.
The smallest base displayed by the program should be 2.
The program's output must correspond to the task conditions.

package com.codegym.task.task30.task3010; /* Smallest possible radix */ public class Solution { public static void main(String[] args) { try{ String s=args[0]; int max=0; try{ int i=Integer.parseInt(s); if (i<=1) System.out.println("2"); else if (i>=9) System.out.println("10"); else System.out.println(i+1); }catch (NumberFormatException e){ s=s.toUpperCase(); byte[] arr=s.getBytes(); for(int j=0;j<arr.length;j++){ if((int)arr[j]<48||(int)arr[j]>57&&(int)arr[j]<65||(int)arr[j]>90){ System.out.println("Invalid"); return;}} for(int k=0;k< arr.length;k++){ if((int)arr[k]>max)max=(int)arr[k]; } System.out.println(max-54); } }catch (Exception e){ }} }

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Justin Johnson

Level 31 , Clearwater, United States

30 October 2020, 02:56

solution

package com.codegym.task.task30.task3010; /* Smallest possible radix */ public class Solution { public static void main(String[] args) { try{ String s=args[0]; if(s.equals("")){ System.out.println("Invalid"); return; } int max=0; try{ int i=Integer.parseInt(s); String[] arr=s.split(""); int r=0; for(int z=0;z<arr.length;z++){ if(Integer.parseInt(arr[z])>r)r=Integer.parseInt(arr[z]); } if(r<2) System.out.println(2); else System.out.println(r+1); }catch (NumberFormatException e){ s=s.toUpperCase(); byte[] arr=s.getBytes(); for(int j=0;j<arr.length;j++){ if((int)arr[j]<48||(int)arr[j]>57&&(int)arr[j]<65||(int)arr[j]>90){ System.out.println("Invalid"); return;}} for(int k=0;k< arr.length;k++){ if((int)arr[k]>max)max=(int)arr[k]; } System.out.println(max-54); } }catch (Exception e){ }} }

Guadalupe Gagnon

Level 37 , Tampa, United States

30 October 2020, 02:36

useful

I think the problem with your code is lines 14-17. Take for example a string such as "1010", this code would output "10" because that number is not less than or equal to 1, but is greater than or equal to 9. May I suggest, as a different approach, creating a Map<Character, Integer> object that contains all the valid chars (0-9, A-Z). Then instead of something that looks like if(this || that && another || something) you could instead do something like this:

if(!Map.containsKey(char)) invalid; // if an invalid char is present
else { // otherwise save the maxRad
   track maxRad;
}

The Integer would be for the maxRad of the lowest base if the char is present, so: '0' = 2 '1' = 2 '2' = 3 '4' = 5 .... 'Y' = 35 'Z' = 36 then you just keep track of the max intValue from the chars of the string as your answer.

Justin Johnson

Level 31 , Clearwater, United States

30 October 2020, 02:49

i guess i was confused on how it works...so if a string "765" was entered...the output should be 8?

Guadalupe Gagnon

Level 37 , Tampa, United States

30 October 2020, 02:51

Yes, the lowest Radix of that number would be eight as a base eight number would include the numbers 0-7, and seven being the highest in that number means it couldn't be anything lower.

Justin Johnson

Level 31 , Clearwater, United States

30 October 2020, 02:55

thank you...i got it now. you are always super helpful and I really appreciate it

Guadalupe Gagnon

Level 37 , Tampa, United States

30 October 2020, 03:10

Anytime.

Justin Johnson

Level 31 , Clearwater, United States

30 October 2020, 01:40

package com.codegym.task.task30.task3010; /* Smallest possible radix */ public class Solution { public static void main(String[] args) { try{ String s=args[0]; if(s.equals("")){ System.out.println("Invalid"); return; } int max=0; try{ int i=Integer.parseInt(s); if(i<0)i=i*(-1); if (i<=1) System.out.println("2"); else if (i>=9) System.out.println("10"); else System.out.println(i+1); }catch (NumberFormatException e){ s=s.toUpperCase(); byte[] arr=s.getBytes(); for(int j=0;j<arr.length;j++){ if((int)arr[j]<48||(int)arr[j]>57&&(int)arr[j]<65||(int)arr[j]>90){ System.out.println("Invalid"); return;}} for(int k=0;k< arr.length;k++){ if((int)arr[k]>max)max=(int)arr[k]; } System.out.println(max-54); } }catch (Exception e){ }} }

Justin Johnson

Level 31 , Clearwater, United States

30 October 2020, 01:39

i also added a conditional for negative numbers

Justin Johnson

Level 31 , Clearwater, United States

30 October 2020, 01:35

i added a conditional for an empty input to equal invalid