diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5f81826
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+.idea
+.gradle
+build/
\ No newline at end of file
diff --git a/TrieImpl1/build.gradle b/TrieImpl1/build.gradle
new file mode 100644
index 0000000..d5d5486
--- /dev/null
+++ b/TrieImpl1/build.gradle
@@ -0,0 +1,14 @@
+group 'ru.spbau.shevchenko'
+version '1.0-SNAPSHOT'
+
+apply plugin: 'java'
+
+sourceCompatibility = 1.5
+
+repositories {
+ mavenCentral()
+}
+
+dependencies {
+ testCompile group: 'junit', name: 'junit', version: '4.11'
+}
diff --git a/TrieImpl1/gradle/wrapper/gradle-wrapper.jar b/TrieImpl1/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..ca78035
Binary files /dev/null and b/TrieImpl1/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/TrieImpl1/gradle/wrapper/gradle-wrapper.properties b/TrieImpl1/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..3566417
--- /dev/null
+++ b/TrieImpl1/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Wed Oct 05 00:00:54 MSK 2016
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.13-bin.zip
diff --git a/TrieImpl1/gradlew b/TrieImpl1/gradlew
new file mode 100755
index 0000000..27309d9
--- /dev/null
+++ b/TrieImpl1/gradlew
@@ -0,0 +1,164 @@
+#!/usr/bin/env bash
+
+##############################################################################
+##
+## Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG=`dirname "$PRG"`"/$link"
+ fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+ echo "$*"
+}
+
+die ( ) {
+ echo
+ echo "$*"
+ echo
+ exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+ CYGWIN* )
+ cygwin=true
+ ;;
+ Darwin* )
+ darwin=true
+ ;;
+ MINGW* )
+ msys=true
+ ;;
+ NONSTOP* )
+ nonstop=true
+ ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ if [ ! -x "$JAVACMD" ] ; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+ fi
+else
+ JAVACMD="java"
+ which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+ MAX_FD_LIMIT=`ulimit -H -n`
+ if [ $? -eq 0 ] ; then
+ if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+ MAX_FD="$MAX_FD_LIMIT"
+ fi
+ ulimit -n $MAX_FD
+ if [ $? -ne 0 ] ; then
+ warn "Could not set maximum file descriptor limit: $MAX_FD"
+ fi
+ else
+ warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+ fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+ GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+ APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+ CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+ JAVACMD=`cygpath --unix "$JAVACMD"`
+
+ # We build the pattern for arguments to be converted via cygpath
+ ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+ SEP=""
+ for dir in $ROOTDIRSRAW ; do
+ ROOTDIRS="$ROOTDIRS$SEP$dir"
+ SEP="|"
+ done
+ OURCYGPATTERN="(^($ROOTDIRS))"
+ # Add a user-defined pattern to the cygpath arguments
+ if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+ OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+ fi
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ i=0
+ for arg in "$@" ; do
+ CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+ CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
+
+ if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
+ eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+ else
+ eval `echo args$i`="\"$arg\""
+ fi
+ i=$((i+1))
+ done
+ case $i in
+ (0) set -- ;;
+ (1) set -- "$args0" ;;
+ (2) set -- "$args0" "$args1" ;;
+ (3) set -- "$args0" "$args1" "$args2" ;;
+ (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+ (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+ (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+ (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+ (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+ (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+ esac
+fi
+
+# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
+function splitJvmOpts() {
+ JVM_OPTS=("$@")
+}
+eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
+JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+
+exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"
diff --git a/TrieImpl1/gradlew.bat b/TrieImpl1/gradlew.bat
new file mode 100644
index 0000000..f6d5974
--- /dev/null
+++ b/TrieImpl1/gradlew.bat
@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/TrieImpl1/settings.gradle b/TrieImpl1/settings.gradle
new file mode 100644
index 0000000..3d66ef9
--- /dev/null
+++ b/TrieImpl1/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name = 'TrieImpl1'
+
diff --git a/TrieImpl1/src/main/java/StreamSerializable.java b/TrieImpl1/src/main/java/StreamSerializable.java
new file mode 100644
index 0000000..3238c85
--- /dev/null
+++ b/TrieImpl1/src/main/java/StreamSerializable.java
@@ -0,0 +1,13 @@
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+public interface StreamSerializable {
+
+ void serialize(OutputStream out) throws IOException;
+
+ /**
+ * Replace current state with data from input stream
+ */
+ void deserialize(InputStream in) throws IOException;
+}
\ No newline at end of file
diff --git a/TrieImpl1/src/main/java/Trie.java b/TrieImpl1/src/main/java/Trie.java
new file mode 100644
index 0000000..b2ce71c
--- /dev/null
+++ b/TrieImpl1/src/main/java/Trie.java
@@ -0,0 +1,29 @@
+public interface Trie {
+ /**
+ * Expected complexity: O(|element|)
+ * @return true if this set did not already contain the specified
+ * element
+ */
+ boolean add(String element);
+
+ /**
+ * Expected complexity: O(|element|)
+ */
+ boolean contains(String element);
+
+ /**
+ * Expected complexity: O(|element|)
+ * @return true if this set contained the specified element
+ */
+ boolean remove(String element);
+
+ /**
+ * Expected complexity: O(1)
+ */
+ int size();
+
+ /**
+ * Expected complexity: O(|prefix|)
+ */
+ int howManyStartsWithPrefix(String prefix);
+}
\ No newline at end of file
diff --git a/TrieImpl1/src/main/java/TrieImpl.java b/TrieImpl1/src/main/java/TrieImpl.java
new file mode 100644
index 0000000..7a01e64
--- /dev/null
+++ b/TrieImpl1/src/main/java/TrieImpl.java
@@ -0,0 +1,154 @@
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+public class TrieImpl implements Trie, StreamSerializable {
+ private static final int NODE_BEGIN = 100;
+ private static final int NODE_END = 101;
+ private static final int ALPHABET = 52;
+
+ private TrieNode root;
+ private int size;
+
+ static class TrieNode{
+ TrieNode[] next;
+ int count;
+ boolean terminal;
+ private static int code(char c){
+ if('a' <= c && c <= 'z') {
+ return c - 'a';
+ }
+ else {
+ return c - 'A' + 26;
+ }
+ }
+ private TrieNode(){
+ next = new TrieNode[ALPHABET];
+ count = 0;
+ }
+ }
+
+ public TrieImpl(){
+ root = new TrieNode();
+ }
+
+ @Override
+ public boolean add(String element) {
+ if (contains(element)) {
+ return false;
+ }
+ TrieNode current = root;
+ for (int i = 0; i < element.length(); i++){
+ int charCode = TrieNode.code(element.charAt(i));
+ if (current.next[charCode] == null){
+ current.next[charCode] = new TrieNode();
+ }
+ current.count++;
+ current = current.next[charCode];
+ }
+ size++;
+ current.terminal = true;
+ current.count++;
+ return true;
+ }
+
+ @Override
+ public boolean contains(String element) {
+ TrieNode current = root;
+ for (int i = 0; i < element.length(); i++){
+ int charCode = TrieNode.code(element.charAt(i));
+ if (current.next[charCode] == null) {
+ return false;
+ }
+ current = current.next[charCode];
+ }
+ return current.terminal;
+ }
+
+ @Override
+ public boolean remove(String element) {
+ if (!contains(element)){
+ return false;
+ }
+ size--;
+ TrieNode current = root;
+ for (int i = 0; i < element.length(); i++){
+ current.count--;
+ int charCode = TrieNode.code(element.charAt(i));
+ if (current.next[charCode].count == 1) {
+ current.next[charCode] = null;
+ return true;
+ }
+ current = current.next[charCode];
+ }
+ current.count--;
+ current.terminal = false;
+ return true;
+ }
+
+ @Override
+ public int howManyStartsWithPrefix(String prefix) {
+ TrieNode current = root;
+ for (int i = 0; i < prefix.length(); i++){
+ int charCode = TrieNode.code(prefix.charAt(i));
+ if (current.next[charCode] == null){
+ return 0;
+ }
+ current = current.next[charCode];
+ }
+ return current.count;
+ }
+
+ @Override
+ public int size() {
+ return size;
+ }
+
+ @Override
+ public void deserialize(InputStream in) throws IOException {
+ size = 0;
+ root = parse(in);
+ setCount(root);
+ }
+
+ @Override
+ public void serialize(OutputStream out) throws IOException {
+ output(root, out);
+ }
+
+ private void setCount(TrieNode root){
+ root.count = root.terminal ? 1 : 0;
+ for (int i = 0; i < ALPHABET; i++) {
+ if (root.next[i] != null){
+ setCount(root.next[i]);
+ root.count += root.next[i].count;
+ }
+ }
+ }
+ private TrieNode parse(InputStream in) throws IOException {
+ in.read();
+ TrieNode result = new TrieNode();
+ result.terminal = in.read() == 1;
+ size += result.terminal ? 1 : 0;
+ while(true){
+ int edgeChar = in.read();
+ if (edgeChar == NODE_END){
+ return result;
+ }
+ else{
+ result.next[edgeChar] = parse(in);
+ }
+ }
+ }
+ private void output(TrieNode current, OutputStream out) throws IOException{
+ out.write(NODE_BEGIN);
+ out.write(current.terminal ? 1 : 0);
+ for (int i = 0; i < ALPHABET; i++) {
+ if (current.next[i] != null) {
+ out.write(i);
+ output(current.next[i], out);
+ }
+ }
+ out.write(NODE_END);
+ }
+}
diff --git a/TrieImpl1/src/test/java/TrieImplTest.java b/TrieImpl1/src/test/java/TrieImplTest.java
new file mode 100644
index 0000000..e903e06
--- /dev/null
+++ b/TrieImpl1/src/test/java/TrieImplTest.java
@@ -0,0 +1,186 @@
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by ilya on 10/5/16.
+ */
+public class TrieImplTest {
+ @Test
+ public void addContains() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ assertFalse(trie.contains("ab"));
+ String hello = "hello";
+ trie.add(hello);
+ for (int i = 1; i < hello.length(); i++){
+ assertFalse(trie.contains(hello.substring(0,i)));
+ }
+ assertTrue(trie.contains(hello));
+
+ trie.add(hello.substring(0,1));
+ for (int i = 2; i < hello.length(); i++){
+ assertFalse(trie.contains(hello.substring(0,i)));
+ }
+ assertTrue(trie.contains(hello));
+ assertTrue(trie.contains(hello.substring(0,1)));
+ }
+
+ @Test
+ public void addRemove() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ trie.add("abaca");
+ assertTrue(trie.contains("abaca"));
+ trie.remove("abaca");
+ assertFalse(trie.contains("abaca"));
+ trie.remove("abaca");
+ assertFalse(trie.contains("abaca"));
+
+ trie.add("abaca");
+ trie.add("abaca");
+ assertTrue(trie.contains("abaca"));
+ trie.remove("abaca");
+ assertFalse(trie.contains("abaca"));
+ }
+
+ @Test
+ public void removePrefix() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ assertTrue(trie.add("abacad"));
+ trie.add("abadab");
+ trie.add("aba");
+ assertEquals(3, trie.howManyStartsWithPrefix("aba"));
+ assertTrue(trie.remove("aba"));
+ assertEquals(2, trie.howManyStartsWithPrefix("aba"));
+ trie.add("aba");
+ assertEquals(3, trie.howManyStartsWithPrefix("aba"));
+ trie.remove("abacad");
+ assertEquals(2, trie.howManyStartsWithPrefix("aba"));
+ }
+
+ @Test
+ public void removeSize() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ trie.add("abaca");
+ trie.add("bacaba");
+ assertEquals(2, trie.size());
+ trie.remove("abacad");
+ assertEquals(2, trie.size());
+ trie.remove("abac");
+ assertEquals(2, trie.size());
+ trie.remove("abaca");
+ assertEquals(1, trie.size());
+ }
+
+ @Test
+ public void lowerUpper() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ trie.add("a");
+ trie.add("z");
+ trie.add("A");
+ trie.add("Z");
+ assertEquals(4, trie.size());
+ trie.remove("a");
+ assertEquals(3, trie.size());
+ trie.remove("A");
+ assertEquals(2, trie.size());
+ trie.remove("z");
+ assertEquals(1, trie.size());
+ trie.remove("Z");
+ assertEquals(0, trie.size());
+ }
+
+ @Test
+ public void howManyStartsWithPrefix() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ assertEquals(0, trie.howManyStartsWithPrefix(""));
+
+ trie.add("hello");
+ assertEquals(1, trie.howManyStartsWithPrefix("hell"));
+ trie.add("hell");
+ assertEquals(2, trie.howManyStartsWithPrefix("hell"));
+ trie.add("hella");
+ assertEquals(3, trie.howManyStartsWithPrefix("hell"));
+
+ trie.add("hello");
+ assertEquals(3, trie.howManyStartsWithPrefix("hell"));
+ trie.add("hell");
+ assertEquals(3, trie.howManyStartsWithPrefix("hell"));
+ trie.add("hella");
+ assertEquals(3, trie.howManyStartsWithPrefix("hell"));
+ assertEquals(3, trie.howManyStartsWithPrefix(""));
+ assertEquals(0, trie.howManyStartsWithPrefix("hellb"));
+ }
+
+ @Test
+ public void size() throws Exception {
+ TrieImpl trie = new TrieImpl();
+ assertEquals(0, trie.size());
+
+ trie.add("a");
+ assertEquals(1, trie.size());
+ trie.add("a");
+ assertEquals(1, trie.size());
+ trie.add("ab");
+ assertEquals(2, trie.size());
+ trie.add("b");
+ assertEquals(3, trie.size());
+ }
+
+ @Test
+ public void serialization1() throws Exception { // deserialize to blank trie
+ TrieImpl trie = new TrieImpl();
+ trie.add("a");
+ trie.add("abba");
+ trie.add("bac");
+ trie.add("bacardo");
+ trie.add("abbc");
+
+ ByteArrayOutputStream out = new ByteArrayOutputStream(100);
+ trie.serialize(out);
+ byte[] buf = out.toByteArray();
+ ByteArrayInputStream in = new ByteArrayInputStream(buf);
+ trie = new TrieImpl();
+ trie.deserialize(in);
+
+ assertTrue(trie.contains("a"));
+ assertTrue(trie.contains("abba"));
+ assertTrue(trie.contains("bac"));
+ assertTrue(trie.contains("bacardo"));
+ assertTrue(trie.contains("abbc"));
+
+ assertEquals(5, trie.size());
+ assertEquals(3, trie.howManyStartsWithPrefix("a"));
+ assertEquals(2, trie.howManyStartsWithPrefix("bac"));
+ assertEquals(1, trie.howManyStartsWithPrefix("baca"));
+ }
+ @Test
+ public void serialization2() throws Exception { // deserialize to filled trie
+ TrieImpl trie = new TrieImpl();
+ trie.add("a");
+ trie.add("abba");
+ trie.add("bac");
+ trie.add("bacardo");
+ trie.add("abbc");
+
+ ByteArrayOutputStream out = new ByteArrayOutputStream(100);
+ trie.serialize(out);
+ byte[] buf = out.toByteArray();
+ ByteArrayInputStream in = new ByteArrayInputStream(buf);
+ trie.deserialize(in);
+
+ assertTrue(trie.contains("a"));
+ assertTrue(trie.contains("abba"));
+ assertTrue(trie.contains("bac"));
+ assertTrue(trie.contains("bacardo"));
+ assertTrue(trie.contains("abbc"));
+
+ assertEquals(5, trie.size());
+ assertEquals(3, trie.howManyStartsWithPrefix("a"));
+ assertEquals(2, trie.howManyStartsWithPrefix("bac"));
+ assertEquals(1, trie.howManyStartsWithPrefix("baca"));
+ }
+
+}
\ No newline at end of file