Finished parts 1, 2, 3.

pom.xml

@@ -7,6 +7,18 @@
     <groupId>io.zipcoder</groupId>
     <artifactId>collections</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.7</source>
+                    <target>1.7</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 
     <dependencies>
         <dependency>

src/main/java/io/zipcoder/ParenChecker.java

@@ -1,4 +1,239 @@
 package io.zipcoder;
 
+import java.util.Arrays;
+import java.util.EnumSet;
+import java.util.Stack;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.*;
+
 public class ParenChecker {
+
+    private String inputExpression;
+    private Stack<String> stack;
+    private EnumSet<ParenStrings> parenStrings;
+
+
+    public ParenChecker() {
+        this.stack = new Stack<String>();
+        this.parenStrings = EnumSet.allOf(ParenStrings.class);
+    }
+
+    public ParenChecker(String inputExpression) {
+        this.inputExpression = inputExpression;
+        this.stack = new Stack<String>();
+        this.parenStrings = EnumSet.allOf(ParenStrings.class);
+    }
+
+    public Stack<String> getStack() {
+        return stack;
+    }
+
+    public boolean isInputLengthEven(String input) {
+        boolean isInputLengthEven = true;
+        if (input.length() % 2 != 0) {
+            isInputLengthEven = false;
+        }
+        return isInputLengthEven;
+    }
+
+    public boolean isFirstCharCorrect(String input) {
+        boolean isFirstCharCorrect = true;
+        String incorrectFirstCharStringPattern = "^[)}\\]>]";
+        Pattern incorrectFirstCharPattern = Pattern.compile(incorrectFirstCharStringPattern);
+        Matcher firstCharMatcher = incorrectFirstCharPattern.matcher(input);
+
+        if (firstCharMatcher.find()) {
+            isFirstCharCorrect = false;
+        }
+        return isFirstCharCorrect;
+    }
+
+    public boolean isLastCharCorrect(String input) {
+        boolean isLastCharCorrect = true;
+        String incorrectLastCharStringPattern = "[({\\[<]$";
+
+        Pattern incorrectLastCharPattern = Pattern.compile(incorrectLastCharStringPattern);
+        Matcher lastCharMatcher = incorrectLastCharPattern.matcher(input);
+
+        if (lastCharMatcher.find()) {
+            isLastCharCorrect = false;
+        }
+        return isLastCharCorrect;
+    }
+
+    public void addOnlyParenStringsToStack(String input) {
+        String[] inputStringArray = input.split("");
+
+        String correctStrings = "[(){}\\[\\]<>\"\']$";
+        Pattern correctStringsPattern = Pattern.compile(correctStrings);
+//        System.out.println("String entering addOnlyParenStringsToStack: ");
+//        System.out.println(input);
+
+        for (String string : inputStringArray) {
+            Matcher correctStringsMatcher = correctStringsPattern.matcher(string);
+            if (correctStringsMatcher.find()) {
+                stack.add(string);
+            }
+        }
+//        System.out.println("Stack leaving addOnlyParenStringsToStack: ");
+//        System.out.println(this.getStackElementsAsString());
+    }
+
+    public boolean areAllParensPaired(String input) {
+        boolean areAllParensPaired = true;
+
+        this.addOnlyParenStringsToStack(input);
+        String cleanedInput = this.getStackElementsAsString();
+        if (! (this.isFirstCharCorrect(cleanedInput) && this.isLastCharCorrect(cleanedInput)) ) {
+            areAllParensPaired = false;
+            return areAllParensPaired;
+        }
+//        System.out.println("Stack inside areAllParensPaired: ");
+//        System.out.println(this.getStackElementsAsString());
+
+        for (int i = 0; i < stack.size() - 1; i++) {
+
+            // SQUIGGLY CHECK
+            if (stack.get(i).equals("{")) {
+                if (stack.get(i + 1).equals("}")) {
+                    stack.remove(i);
+                    stack.remove(i);
+                    if (i == 0) i--;
+                    else i -= 2;
+                    continue;
+                }
+                if ( stack.get(i + 1).equals("]") || stack.get(i + 1).equals(")")
+                     || stack.get(i + 1).equals(">") ) {
+                    break;
+                }
+            }
+
+            // BRACKET CHECK
+            if (stack.get(i).equals("[")) {
+                if (stack.get(i + 1).equals("]")) {
+                    stack.remove(i);
+                    stack.remove(i);
+                    if (i == 0) i--;
+                    else i -= 2;
+                    continue;
+                }
+                if ( stack.get(i + 1).equals("}") || stack.get(i + 1).equals(")")
+                     || stack.get(i + 1).equals(">") ) {
+                    break;
+                }
+            }
+
+            // PARENTHESIS CHECK
+            if (stack.get(i).equals("(")) {
+                if (stack.get(i + 1).equals(")")) {
+                    stack.remove(i);
+                    stack.remove(i);
+                    if (i == 0) i--;
+                    else i -= 2;
+                    continue;
+                }
+                if ( stack.get(i + 1).equals("}") || stack.get(i + 1).equals("]")
+                     || stack.get(i + 1).equals(">") ) {
+                    break;
+                }
+            }
+
+            // DIAMONDS CHECK
+            if (stack.get(i).equals("<")) {
+                if (stack.get(i + 1).equals(">")) {
+                    stack.remove(i);
+                    stack.remove(i);
+                    if (i == 0) i--;
+                    else i -= 2;
+                    continue;
+                }
+                if ( stack.get(i + 1).equals("}") || stack.get(i + 1).equals("]")
+                     || stack.get(i + 1).equals(")") ) {
+                    break;
+                }
+            }
+
+            // DOUBLE_QUOTE CHECK
+            if (stack.get(i).equals("\"")) {
+                if (stack.get(i + 1).equals("\"")) {
+                    stack.remove(i);
+                    stack.remove(i);
+                    if (i == 0) i--;
+                    else i -= 2;
+                    continue;
+                }
+                if ( stack.get(i + 1).equals("}") || stack.get(i + 1).equals("]")
+                     || stack.get(i + 1).equals(")") || stack.get(i + 1).equals(">") ) {
+                    break;
+                }
+            }
+
+            // SINGLE_QUOTE CHECK
+            if (stack.get(i).equals("\'")) {
+                if (stack.get(i + 1).equals("\'")) {
+                    stack.remove(i);
+                    stack.remove(i);
+                    if (i == 0) i--;
+                    else i -= 2;
+                    continue;
+                }
+                if ( stack.get(i + 1).equals("}") || stack.get(i + 1).equals("]")
+                        || stack.get(i + 1).equals(")") || stack.get(i + 1).equals(">") ) {
+                    break;
+                }
+            }
+
+        } // end of for loop
+
+        if (stack.size() != 0) {
+            areAllParensPaired = false;
+        }
+        return areAllParensPaired;
+    }
+
+    public String getStackElementsAsString() {
+        StringBuilder sb = new StringBuilder();
+        for (String string : stack) {
+            sb.append(string);
+        }
+        return sb.toString();
+    }
+
+    public boolean isFinalStackSizeZero() {
+        boolean isFinalStackSizeZero = false;
+        if (stack.size() == 0) {
+            isFinalStackSizeZero = true;
+        }
+        return isFinalStackSizeZero;
+    }
+
+    public void makeStackSizeZero() {
+        stack.clear();
+    }
+
+    public static void main(String[] args){
+        ParenChecker parenChecker = new ParenChecker();
+
+        String inputExpression = "1918-203948-209{}";
+        parenChecker.addOnlyParenStringsToStack(inputExpression);
+        String cleanedInput = parenChecker.getStackElementsAsString();
+        parenChecker.makeStackSizeZero();
+
+        System.out.println("FINAL RESULT");
+        System.out.println("Are parens paired?: " + parenChecker.areAllParensPaired(inputExpression));
+        System.out.println("Original String: " + inputExpression);
+        System.out.println("Final Stack:     " + parenChecker.getStackElementsAsString());
+        System.out.println();
+
+        System.out.println("REQUIREMENTS (should all be true)");
+        System.out.println("Cleaned String:  " + cleanedInput);
+        System.out.println("Is Cleaned String even?:  " + parenChecker.isInputLengthEven(cleanedInput));
+        System.out.println("Is first String correct?: " + parenChecker.isFirstCharCorrect(cleanedInput));
+        System.out.println("Is last String correct?:  " + parenChecker.isLastCharCorrect(cleanedInput));
+        System.out.println("Is Final Stack size = 0?: " + parenChecker.isFinalStackSizeZero());
+        System.out.println();
+
+
+    }
 }

src/main/java/io/zipcoder/ParenStrings.java

@@ -0,0 +1,37 @@
+package io.zipcoder;
+
+public enum ParenStrings {
+
+    PARENTHESES("(", ")"),
+    BRACKETS("[", "]"),
+    SQUIGGLIES("{", "}"),
+    DIAMONDS("<", ">"),
+    DOUBLE_QUOTES("\"", "\""),
+    SINGLE_QUOTES("\'", "\'");
+
+    private final String openingString;
+    private final String closingString;
+
+    ParenStrings(String openingString, String closingString) {
+        this.openingString = openingString;
+        this.closingString = closingString;
+    }
+
+    public String getOpeningString() {
+        return openingString;
+    }
+
+    public String getClosingString() {
+        return closingString;
+    }
+
+    public String getOppositeString(String input) {
+        String oppositeString = "";
+        if (input.equals(openingString)) {
+            oppositeString = closingString;
+        } else if (input.equals(closingString)) {
+            oppositeString = openingString;
+        }
+        return oppositeString;
+    }
+}

src/main/java/io/zipcoder/WC.java

@@ -2,11 +2,15 @@
 
 import java.io.FileNotFoundException;
 import java.io.FileReader;
-import java.util.Iterator;
-import java.util.Scanner;
+import java.lang.reflect.Array;
+import java.util.*;
+import java.util.Map.Entry;
 
 public class WC {
+
     private Iterator<String> si;
+    private LinkedHashMap<String, Integer> linkedHashMap;
+    private final String DELIMITER = "[^a-zA-Z0-9]+";
 
     public WC(String fileName) {
         try {
@@ -15,9 +19,66 @@ public WC(String fileName) {
             System.out.println(fileName + " Does Not Exist");
             System.exit(-1);
         }
+        linkedHashMap = new LinkedHashMap<String, Integer>();
     }
 
     public WC(Iterator<String> si) {
         this.si = si;
+        linkedHashMap = new LinkedHashMap<String, Integer>();
+    }
+
+    public LinkedHashMap<String, Integer> getLinkedHashMap() {
+        return linkedHashMap;
+    }
+
+    public void addWordsToLinkedHashMap() {
+        while(si.hasNext()) {
+            String[] words = si.next().split(DELIMITER);
+            for (String word : words) {
+                word = word.toLowerCase();
+                if (linkedHashMap.get(word) == null) {
+                    linkedHashMap.put(word, 1);
+                } else {
+                    linkedHashMap.put(word, linkedHashMap.get(word) + 1);
+                }
+            }
+        }
+    }
+
+    public String getWordCountInDescendingOrder() {
+        List<Entry<String, Integer>> wordCount = new ArrayList<>(linkedHashMap.entrySet());
+        StringBuilder sb = new StringBuilder();
+
+        Collections.sort(wordCount, new Comparator<Entry>() {
+            public int compare(Entry e1, Entry e2) {
+                if ( (int)e2.getValue() == (int)e1.getValue() ) {
+                    return 0;
+                } else if ( (int)e1.getValue() > (int)e2.getValue() ) {
+                    return -1;
+                } else
+                    return 1;
+            }
+        });
+
+        sb.append("Count = Word" + "\n");
+        for (Entry entry : wordCount) {
+            sb.append(entry.getValue() + " = " + entry.getKey() + "\n");
+        }
+
+        return sb.toString();
+    }
+
+    public static void main(String[] args) {
+
+        String inputExpression = "first second third fourth";
+        WC wc = new WC(WC.class.getResource("/aeneid.txt").getFile());
+        wc.addWordsToLinkedHashMap();
+        wc.getLinkedHashMap();
+//        for (Entry entry : wc.getLinkedHashMap().entrySet()) {
+//            System.out.println(entry.toString());
+//        }
+
+        System.out.println(wc.getWordCountInDescendingOrder());
+
     }
 }

src/main/resources/aeneid.txt

@@ -0,0 +1,7 @@
+Then to his glance appeared the accurst swordbelt surmounting Turnus' shoulder,
+shining with its familiar studs—the strap Young Pallas wore when Turnus wounded him
+and left him dead upon the field; now Turnus bore that enemy token on his shoulder—enemy still.
+For when the sight came home to him, Aeneas raged at the relic of his anguish worn by this man as trophy.
+Blazing up and terrible in his anger, he called out: "You in your plunder, torn from one of mine,
+shall I be robbed of you? This wound will come from Pallas: Pallas makes this offering,
+and from your criminal blood exacts his due." He sank his blade in fury in Turnus' chest ...