1 task #346
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,28 @@ | ||
| <?xml version="1.0" encoding="UTF-8"?> | ||
| <project xmlns="http://maven.apache.org/POM/4.0.0" | ||
| xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | ||
| xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> | ||
| <parent> | ||
| <artifactId>mipt-java-2016</artifactId> | ||
| <groupId>ru.mipt.java2016</groupId> | ||
| <version>1.0.0</version> | ||
| </parent> | ||
| <modelVersion>4.0.0</modelVersion> | ||
|
|
||
| <artifactId>homework-g596-narsia</artifactId> | ||
| <dependencies> | ||
| <dependency> | ||
| <groupId>ru.mipt.java2016</groupId> | ||
| <artifactId>homework-base</artifactId> | ||
| <version>1.0.0</version> | ||
| </dependency> | ||
| <dependency> | ||
| <groupId>ru.mipt.java2016</groupId> | ||
| <artifactId>homework-tests</artifactId> | ||
| <version>1.0.0</version> | ||
| <scope>test</scope> | ||
| </dependency> | ||
| </dependencies> | ||
|
|
||
|
|
||
| </project> |
Binary file not shown.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,359 @@ | ||
| package ru.mipt.java2016.homework.g596.narsia.task1; | ||
|
|
||
| import ru.mipt.java2016.homework.base.task1.Calculator; | ||
| import ru.mipt.java2016.homework.base.task1.ParsingException; | ||
|
|
||
| import java.util.*; | ||
|
|
||
| // подробное описание работы кода | ||
| // можно найти в файле description | ||
|
There was a problem hiding this comment. Пиши комментарии прямо в коде |
||
|
|
||
|
|
||
| public class MyCalculator implements Calculator { | ||
| private enum SymbolType { DIGIT, POINT, USUAL_OPERATOR, MINUS, SPACE, | ||
| OPENING_BRACKET, CLOSING_BRACKET, FIRST, INVALID } | ||
|
|
||
|
|
||
| private SymbolType whatIsIt(Character symbol) { | ||
|
There was a problem hiding this comment. Не слишком-то похоже на понятное название |
||
| if (Character.isDigit(symbol)) { | ||
| return SymbolType.DIGIT; | ||
| } | ||
| if (symbol.equals('.')) { | ||
| return SymbolType.POINT; | ||
| } | ||
| if ((symbol.equals('+')) || (symbol.equals('*')) || (symbol.equals('/'))) { | ||
| return SymbolType.USUAL_OPERATOR; | ||
| } | ||
| if (symbol.equals('-')) { | ||
| return SymbolType.MINUS; | ||
| } | ||
| if (Character.isWhitespace(symbol)) { | ||
| return SymbolType.SPACE; | ||
| } | ||
| if (symbol.equals('(')) { | ||
| return SymbolType.OPENING_BRACKET; | ||
| } | ||
| if (symbol.equals(')')) { | ||
| return SymbolType.CLOSING_BRACKET; | ||
| } | ||
| if (symbol.equals('~')) { | ||
| return SymbolType.FIRST; | ||
| } | ||
| return SymbolType.INVALID; | ||
|
There was a problem hiding this comment. Во многих языках программирования есть такая штука, как assert. Его используют, чтобы поймать некорректные состояния. Этот твой |
||
| } | ||
|
|
||
|
|
||
| private void isAlmostValid(String expression) throws ParsingException { | ||
| if (expression == null) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| char prevSymbol = '~'; | ||
| char curSymbol; | ||
| char importantPrevSymbol = '~'; | ||
| boolean pointFlag = false; | ||
| boolean spaceFlag = false; | ||
|
|
||
| for (int index = 0; index < expression.length(); ++index) { | ||
| curSymbol = expression.charAt(index); | ||
| switch (whatIsIt(curSymbol)) { | ||
| case DIGIT: | ||
| if (whatIsIt(prevSymbol) == SymbolType.SPACE) { | ||
| if ((whatIsIt(importantPrevSymbol) == SymbolType.DIGIT) || | ||
| (whatIsIt(importantPrevSymbol) == SymbolType.CLOSING_BRACKET)) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| } | ||
| if (whatIsIt(prevSymbol) == SymbolType.CLOSING_BRACKET) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| break; | ||
|
|
||
| case POINT: | ||
| if (whatIsIt(prevSymbol) == SymbolType.DIGIT) { | ||
| if (!pointFlag) { | ||
| pointFlag = true; | ||
| } else { | ||
| throw new ParsingException("2 points in one number"); | ||
| } | ||
| } else { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| break; | ||
|
|
||
| case USUAL_OPERATOR: | ||
| if ((whatIsIt(importantPrevSymbol) == SymbolType.USUAL_OPERATOR) || | ||
| (importantPrevSymbol == '(') || (importantPrevSymbol == '~') || | ||
| (importantPrevSymbol == '.')) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| if (whatIsIt(importantPrevSymbol) == SymbolType.DIGIT) { | ||
| pointFlag = false; | ||
| } | ||
| break; | ||
|
|
||
| case MINUS: | ||
| if (importantPrevSymbol == '.') { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| if (whatIsIt(importantPrevSymbol) == SymbolType.DIGIT) { | ||
| pointFlag = false; | ||
| } | ||
| break; | ||
|
|
||
| case SPACE: | ||
| if (prevSymbol == '.') { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| if (whatIsIt(prevSymbol) == SymbolType.DIGIT) { | ||
| pointFlag = false; | ||
| } | ||
| break; | ||
|
|
||
| case OPENING_BRACKET: | ||
| if ((whatIsIt(importantPrevSymbol) == SymbolType.DIGIT) || | ||
| (importantPrevSymbol == '.') || (importantPrevSymbol == ')')) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| break; | ||
|
|
||
| case CLOSING_BRACKET: | ||
| if (whatIsIt(importantPrevSymbol) == SymbolType.DIGIT) { | ||
| pointFlag = false; | ||
| } | ||
| if ((importantPrevSymbol == '.') || (importantPrevSymbol == '(') || | ||
| (importantPrevSymbol == '~') || | ||
| (whatIsIt(importantPrevSymbol) == SymbolType.USUAL_OPERATOR) || | ||
| (importantPrevSymbol == '-')) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| break; | ||
|
|
||
| default: | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| prevSymbol = curSymbol; | ||
| if (whatIsIt(curSymbol) != SymbolType.SPACE) { | ||
| importantPrevSymbol = curSymbol; | ||
| spaceFlag = true; | ||
| } | ||
| } | ||
| if (!spaceFlag) { | ||
| throw new ParsingException("Invalid expression"); | ||
| } | ||
| } | ||
|
|
||
|
|
||
| private String removeSpaces(String expression) { | ||
| StringBuilder result = new StringBuilder(expression.length()); | ||
| for (int index = 0; index < expression.length(); ++index) { | ||
| if (!Character.isWhitespace(expression.charAt(index))) { | ||
| result.append(expression.charAt(index)); | ||
| } | ||
| } | ||
| return result.toString(); | ||
| } | ||
|
|
||
|
|
||
| private String removeUnaryMinuses(String expressionWithoutSpaces) { | ||
| expressionWithoutSpaces = expressionWithoutSpaces.concat("~"); | ||
| StringBuilder result = new StringBuilder(expressionWithoutSpaces.length()); | ||
| boolean bracketFlag = false; | ||
| for (int index = 0; index < expressionWithoutSpaces.length(); ++index) { | ||
| if (expressionWithoutSpaces.charAt(index) == '-') { | ||
| if (index == 0) { | ||
| result.append('0'); | ||
| } else { | ||
| switch (whatIsIt(expressionWithoutSpaces.charAt(index - 1))) { | ||
| case OPENING_BRACKET: | ||
| result.append("0-"); | ||
| continue; | ||
| case USUAL_OPERATOR: | ||
| case MINUS: | ||
| result.append("(0-"); | ||
| bracketFlag = true; | ||
| continue; | ||
| default: | ||
| break; | ||
| } | ||
| } | ||
| } | ||
| if ((!Character.isDigit(expressionWithoutSpaces.charAt(index))) && | ||
| (expressionWithoutSpaces.charAt(index) != '.') && (index > 0) && (bracketFlag)) { | ||
| result.append(")"); | ||
| bracketFlag = false; | ||
| } | ||
| if (expressionWithoutSpaces.charAt(index) != '~') { | ||
| result.append(expressionWithoutSpaces.charAt(index)); | ||
| } | ||
| } | ||
| return result.toString(); | ||
| } | ||
|
|
||
|
|
||
| private int getCode(char first, char second) { | ||
|
There was a problem hiding this comment. Как говорили Великие:
Почему не сделать enum вместо цифр? С ним назначение функции слегка прояснится. Заодно можно будет переименовать |
||
| switch (first) { | ||
| case '~': | ||
| if ((whatIsIt(second) == SymbolType.USUAL_OPERATOR) || | ||
| (second == '-') || (second == '(')) { | ||
| return 1; | ||
| } | ||
| if (second == '~') { | ||
| return 4; | ||
| } | ||
| if (second == ')') { | ||
| return 5; | ||
| } | ||
| case '+': | ||
| case '-': | ||
| if ((second == '*') || (second == '/') || (second == '(')) { | ||
| return 1; | ||
| } | ||
| if ((second == '~') || (second == ')') || | ||
| (second == '+') || (second == '-')) { | ||
| return 2; | ||
| } | ||
| case '*': | ||
| case '/': | ||
| if (second == '(') { | ||
| return 1; | ||
| } | ||
| if ((second == '~') || (second == ')') || | ||
| (whatIsIt(second) == SymbolType.USUAL_OPERATOR) || | ||
| (second == '-')) { | ||
| return 2; | ||
| } | ||
| case '(': | ||
| if ((second == '(') || (whatIsIt(second) == SymbolType.USUAL_OPERATOR) || | ||
| second == '-') { | ||
| return 1; | ||
| } | ||
| if (second == ')') { | ||
| return 3; | ||
| } | ||
| if (second == '~') { | ||
| return 5; | ||
| } | ||
| default: | ||
| return -1; | ||
| } | ||
| } | ||
|
|
||
|
|
||
| private String getRPN(String expression) throws ParsingException { | ||
| expression = expression.concat("~"); | ||
| Character curSymbol; | ||
| Character prevSymbol = '~'; | ||
| Stack<Character> texas = new Stack<>(); | ||
| StringBuilder california = new StringBuilder(expression.length()); | ||
|
There was a problem hiding this comment. То, что в статье, которую ты скинул, есть слова Техас и Калифорния, ещё не значит, что их нужно использовать, как названия переменных. Придумай что-нибудь более говорящее |
||
| texas.push('~'); | ||
|
|
||
| int index = 0; | ||
| while (true) { | ||
|
There was a problem hiding this comment. Как интересно ты в исходном решении заменил |
||
| curSymbol = expression.charAt(index); | ||
| if (index > 0) { | ||
| prevSymbol = expression.charAt(index - 1); | ||
| } | ||
| switch (whatIsIt(curSymbol)) { | ||
| case DIGIT: | ||
| case POINT: | ||
| if ((Character.isDigit(prevSymbol)) || (prevSymbol == '.') || | ||
| (prevSymbol == '~')) { | ||
| california.append(curSymbol); | ||
| ++index; | ||
| } else { | ||
| california.append(" "); | ||
| california.append(curSymbol); | ||
| ++index; | ||
| break; | ||
| } | ||
| continue; | ||
|
|
||
| default: | ||
| break; | ||
| } | ||
|
|
||
| switch (getCode(texas.peek(), curSymbol)) { | ||
| case 1: | ||
| texas.push(curSymbol); | ||
| ++index; | ||
| break; | ||
| case 2: | ||
| california.append(" "); | ||
| california.append(texas.peek()); | ||
| texas.pop(); | ||
| break; | ||
| case 3: | ||
| texas.pop(); | ||
| ++index; | ||
| break; | ||
| case 4: | ||
| return california.toString(); | ||
| case 5: | ||
| throw new ParsingException("Invalid bracket balance"); | ||
| default: | ||
| break; | ||
| } | ||
| } | ||
| } | ||
|
|
||
|
|
||
| private double doOperation(double first, double second, char operator) { | ||
| switch (operator) { | ||
| case '+': | ||
| return first + second; | ||
| case '-': | ||
| //сейчас будет костыль | ||
| if ((first == 0) && (second == 0)) { | ||
| return -0.0; | ||
| } | ||
| return first - second; | ||
| case '*': | ||
| return first * second; | ||
| case '/': | ||
| return first / second; | ||
| default: | ||
| return -1.0; | ||
| } | ||
| } | ||
|
|
||
|
|
||
| @Override | ||
| public double calculate(String expression) throws ParsingException { | ||
| isAlmostValid(expression); | ||
| String withoutSpaces = removeSpaces(expression); | ||
| String withoutSpacesAndUnaryMinuses = removeUnaryMinuses(withoutSpaces); | ||
| String rpn = getRPN(withoutSpacesAndUnaryMinuses); | ||
| Stack<Double> numbers = new Stack<>(); | ||
| Double first; | ||
| Double second; | ||
| StringBuilder curNumber = new StringBuilder(); | ||
| char curChar = '~'; | ||
| char prevChar; | ||
| for (int cnt = 0; cnt < rpn.length(); ++cnt) { | ||
| prevChar = curChar; | ||
| curChar = rpn.charAt(cnt); | ||
| switch (whatIsIt(curChar)) { | ||
| case DIGIT: | ||
| case POINT: | ||
| curNumber.append(curChar); | ||
| break; | ||
| case USUAL_OPERATOR: | ||
| case MINUS: | ||
| second = numbers.peek(); | ||
| numbers.pop(); | ||
| first = numbers.peek(); | ||
| numbers.pop(); | ||
| numbers.push(doOperation(first, second, curChar)); | ||
| break; | ||
| case SPACE: | ||
| if (Character.isDigit(prevChar)) { | ||
| numbers.push(Double.parseDouble(curNumber.toString())); | ||
| curNumber.delete(0, curNumber.length()); | ||
| } | ||
| default: | ||
| break; | ||
| } | ||
| } | ||
| return numbers.peek(); | ||
| } | ||
| } | ||
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Считается плохим тоном импортировать через *. Перечисли всё, что ты импортируешь отдельно