Problem Solutions: 14 Modular calculator problem

makeMH 2018-08-29 11:52:27

Hello,

after putting in example imput data and going through debug mode action by action, everything seems and works okay, but it doesn't work with Test input data. What am I missing here?

package com.company;

import java.util.*;

public class Main {

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);

    int initialNumber;
    String operation = "";
    int number;
    int result;
    boolean end = false;

    initialNumber = in.nextInt();
    result = initialNumber;

    while(end == false) {
        operation = in.next();
        number = in.nextInt();

        switch (operation) {
            case "+":
                result = result + number;
                break;
            case "*":
                result = result * number;
                break;
            case "%":
                result = result % number;
                end = true;
                break;
        }
    }
    System.out.println(result + " ");
}

}

And another question - whenever I put input data into console and press Enter, I have to press Enter again to see the result. Is it common thing or am I missing something there as well?

Thanks!

Quandray 2018-08-29 13:30:26

You've missed the bit that says "though intermediate results could be very large"

Try your code with this test data
10000
* 10000
* 10000
% 7982

makeMH 2018-08-29 14:01:06

Thanks!

Switching to BigInteger solved the problem :)

Quandray 2018-08-30 06:25:38

Using biginteger, misses the whole point of the problem, which is "modular arithmetic".

Irbin_Rd 2023-06-26 05:53:53

My method to perform my modular operation is as follows:

private static int ModularOperation(int startNumber, String[] split) {
     int modulo = Integer.parseInt(split[split.length - 1].split(" ")[1]);
     for (String string : split) {
         String[] values = string.split(" ");
         String operator = values[0];
         int value = Integer.parseInt(values[1]);

         switch ( operator ) {
             case "+":
                 startNumber += value;
                 break;
             case "*":
                 startNumber *= value;
                 break;
             default:
                 startNumber %= value;
         }


         if ( startNumber > module && !operator.equals("%")) {
             startNumber %= module;
         }
     }

     return startNumber;
 }.

If I evaluate with the following data:

initial value : 40
values to evaluate: {"+ 9", "+ 2047", "* 14", "+ 5", "+ 2199", "+ 8404", "+ 710", "+ 621", "* 331" , "+4", "+4763", "*2372", "+5", "+1", "*77", "*807", "+782", "*826", "*9" , "*4928", "+2", "*9", "+99", "+6", "+1", "*186", "+3", "+4354", "+6592" , "+7", "+3", "+87", "+1507", "+63", "*4707", "*3", "+8", "+7", "+1810" , "*9170", "*8", "+97", "*33" , "+10", "*88", "+2923", "*5", "+5136", "+1461", "+375", "%5591"};

When calculating all of the above, I get the result: 3883. But when I send my response it says that I am wrong and it shows me the following result: 5194. Could you correct me what part of my code I am doing wrong.

Rodion (admin) 2023-06-26 06:05:55

Your initial code looks less or more correct, there is no need to use BigInteger as you did at last.

Your input data looks a bit messy, so probably there was some mistake just about parsing data.

It seems you have passed this problem anyway.