# rameshCoder's solution

## to Wordy in the Java Track

Published at Jan 31 2019 · 0 comments
Instructions
Test suite
Solution

#### Note:

This exercise has changed since this solution was written.

Parse and evaluate simple math word problems returning the answer as an integer.

## Iteration 1 — Addition

Add two numbers together.

What is 5 plus 13?

Evaluates to 18.

Handle large numbers and negative numbers.

## Iteration 2 — Subtraction, Multiplication and Division

Now, perform the other three operations.

What is 7 minus 5?

2

What is 6 multiplied by 4?

24

What is 25 divided by 5?

5

## Iteration 3 — Multiple Operations

Handle a set of operations, in sequence.

Since these are verbal word problems, evaluate the expression from left-to-right, ignoring the typical order of operations.

What is 5 plus 13 plus 6?

24

What is 3 plus 2 multiplied by 3?

15 (i.e. not 9)

## Bonus — Exponentials

If you'd like, handle exponentials.

What is 2 raised to the 5th power?

32

# Running the tests

You can run all the tests for an exercise by entering

``````\$ gradle test
``````

## Source

Inspired by one of the generated questions in the Extreme Startup game. https://github.com/rchatley/extreme_startup

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

### WordProblemSolverTest.java

``````import org.junit.Ignore;
import org.junit.Rule;
import org.junit.Test;
import org.junit.Before;
import org.junit.rules.ExpectedException;

import static org.junit.Assert.assertEquals;

public class WordProblemSolverTest {

@Rule
public ExpectedException expectedException = ExpectedException.none();

WordProblemSolver solver;

@Before
public void setup() {
solver = new WordProblemSolver();
}

@Test
public void testSingleAddition1() {
assertEquals(2, solver.solve("What is 1 plus 1?"));
}

@Ignore("Remove to run test")
@Test
public void testSingleAddition2() {
assertEquals(55, solver.solve("What is 53 plus 2?"));
}

@Ignore("Remove to run test")
@Test
public void testSingleAdditionWithNegativeNumbers() {
assertEquals(-11, solver.solve("What is -1 plus -10?"));
}

@Ignore("Remove to run test")
@Test
public void testSingleAdditionOfLargeNumbers() {
assertEquals(45801, solver.solve("What is 123 plus 45678?"));
}

@Ignore("Remove to run test")
@Test
public void testSingleSubtraction() {
assertEquals(16, solver.solve("What is 4 minus -12?"));
}

@Ignore("Remove to run test")
@Test
public void testSingleMultiplication() {
assertEquals(-75, solver.solve("What is -3 multiplied by 25?"));
}

@Ignore("Remove to run test")
@Test
public void testSingleDivision() {
assertEquals(-11, solver.solve("What is 33 divided by -3?"));
}

@Ignore("Remove to run test")
@Test
public void testMultipleAdditions() {
assertEquals(3, solver.solve("What is 1 plus 1 plus 1?"));
}

@Ignore("Remove to run test")
@Test
public void testAdditionThenSubtraction() {
assertEquals(8, solver.solve("What is 1 plus 5 minus -2?"));
}

@Ignore("Remove to run test")
@Test
public void testMultipleSubtractions() {
assertEquals(3, solver.solve("What is 20 minus 4 minus 13?"));
}

@Ignore("Remove to run test")
@Test
public void testSubtractionThenAddition() {
assertEquals(14, solver.solve("What is 17 minus 6 plus 3?"));
}

@Ignore("Remove to run test")
@Test
public void testMultipleMultiplications() {
assertEquals(-12, solver.solve("What is 2 multiplied by -2 multiplied by 3?"));
}

@Ignore("Remove to run test")
@Test
public void testAdditionThenMultiplication() {
assertEquals(-8, solver.solve("What is -3 plus 7 multiplied by -2?"));
}

@Ignore("Remove to run test")
@Test
public void testMultipleDivisions() {
assertEquals(2, solver.solve("What is -12 divided by 2 divided by -3?"));
}

@Ignore("Remove to run test")
@Test
public void testUnknownOperation() {
expectedException.expect(IllegalArgumentException.class);
expectedException.expectMessage("I'm sorry, I don't understand the question!");

solver.solve("What is 52 cubed?");
}

@Ignore("Remove to run test")
@Test
public void testInvalidQuestionFormat() {
expectedException.expect(IllegalArgumentException.class);
expectedException.expectMessage("I'm sorry, I don't understand the question!");

// See https://en.wikipedia.org/wiki/President_of_the_United_States if you really need to know!
solver.solve("Who is the President of the United States?");
}

}``````
``````import java.util.HashSet;
import java.util.Set;
import java.util.Stack;

public class WordProblemSolver {

Set<String> validOperations = new HashSet<>();
public WordProblemSolver() {
}

int solve(String query) {

int result = 0;
String operation = "Init";

for (String term : query.split("\\s")) {
term = term.replace("?", "");

if(term.matches("^-?\\d+")) {
int val = Integer.valueOf(term);
switch (operation) {
case "Init":
result += val;
break;
case "plus":
result += val;
operation = "Done";
break;
case "minus":
result -= val;
operation = "Done";
break;
case "multiplied":
result *= val;
operation = "Done";
break;
case "divided":
result /= val;
operation = "Done";
break;
default:
throw new IllegalArgumentException("I'm sorry, I don't understand the question!");
}

}
else if(validOperations.contains(term.toLowerCase())) {
operation = term;
}
}

if(!operation.equals("Done")) {
throw new IllegalArgumentException("I'm sorry, I don't understand the question!");
}

return result;
}

public static void main(String[] args) {
System.out.println(new WordProblemSolver().solve("What is 52 cubed?"));
}

}``````