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Merge pull request #186 from javaeeeee/binary-search
Binary search
2 parents edba888 + 1d8fa2c commit a47d37e

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7 files changed

+204
-1
lines changed

7 files changed

+204
-1
lines changed

‎config.json

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@@ -52,7 +52,8 @@
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"robot-simulator",
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"bracket-push",
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"pythagorean-triplet",
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"binary-search-tree"
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"binary-search-tree",
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"binary-search"
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],
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"exercises": [
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{
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"slug": "binary-search-tree",
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"difficulty": 1,
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"topics": []
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},
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{
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"slug": "binary-search",
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"difficulty": 1,
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"topics": []
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}
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],
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"deprecated": [

‎exercises/binary-search/build.gradle

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apply plugin: "java"
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apply plugin: "eclipse"
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apply plugin: "idea"
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repositories {
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mavenCentral()
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}
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dependencies {
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testCompile "junit:junit:4.12"
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}
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test {
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testLogging {
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exceptionFormat = 'full'
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events = ["passed", "failed", "skipped"]
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}
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}

‎exercises/binary-search/src/example/java/BinarySearch.java

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import java.util.List;
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public class BinarySearch<T extends Comparable<T>> {
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private List<T> array;
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private int arraySize;
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public BinarySearch(List<T> array) {
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this.array = array;
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this.arraySize = array.size();
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}
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public int indexOf(T value) {
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return search(value);
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}
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public List<T> getArray() {
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return array;
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}
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private int search(T value) {
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int left = 0;
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int right = this.arraySize - 1;
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int middle;
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T element;
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while (left <= right) {
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middle = (int) Math.floor(0.5 * (left + right));
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element = this.array.get(middle);
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if (value.compareTo(element) > 0) {
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left = middle + 1;
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} else if (value.compareTo(element) < 0) {
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right = middle - 1;
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} else {
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return middle;
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}
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}
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return -1;
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}
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}

‎exercises/binary-search/src/main/java/.keep

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‎exercises/binary-search/src/main/java/BinarySearch.java

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public class BinarySearch {
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}

‎exercises/binary-search/src/test/java/.keep

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‎exercises/binary-search/src/test/java/BinarySearchTest.java

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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.List;
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import static org.junit.Assert.assertEquals;
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import org.junit.Ignore;
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import org.junit.Test;
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public class BinarySearchTest {
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public static final List<Integer> EMPTY_LIST
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= Collections.unmodifiableList(new ArrayList<Integer>(0));
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public static final List<Integer> LIST_OF_UNIT_LENGTH
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= Collections.unmodifiableList(
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Arrays.asList(6)
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);
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private static final List<Integer> SORTED_LIST
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= Collections.unmodifiableList(
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Arrays.asList(1, 3, 4, 6, 8, 9, 11)
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);
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public static final List<Integer> SORTED_LIST_OF_ODD_LENGTH
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= Collections.unmodifiableList(
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Arrays.asList(1, 3, 5, 8, 13, 21, 34, 55,
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89, 144, 233, 377, 634)
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);
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public static final List<Integer> SORTED_LIST_OF_EVEN_LENGTH
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= Collections.unmodifiableList(
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Arrays.asList(1, 3, 5, 8, 13, 21, 34, 55,
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89, 144, 233, 377)
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);
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@Test
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public void findsAValueInAnArrayWithOneElement() {
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BinarySearch<Integer> sut = new BinarySearch<>(LIST_OF_UNIT_LENGTH);
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final int value = 6;
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final int actual = sut.indexOf(value);
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final int expected = 0;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void findsAValueInTheMiddleOfAnArray() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST);
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final int value = 6;
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final int actual = sut.indexOf(value);
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final int expected = 3;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void findsAValueAtTheBeginningOfAnArray() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST);
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final int value = 1;
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final int actual = sut.indexOf(value);
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final int expected = 0;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void findsAValueAtTheEndOfAnArray() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST);
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final int value = 11;
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final int actual = sut.indexOf(value);
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final int expected = 6;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void findsAValueInAnArrayOfOddLength() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST_OF_ODD_LENGTH);
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final int value = 144;
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final int actual = sut.indexOf(value);
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final int expected = 9;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void findsAValueInAnArrayOfEvenLength() {
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BinarySearch<Integer> sut
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= new BinarySearch<>(SORTED_LIST_OF_EVEN_LENGTH);
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final int value = 21;
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final int actual = sut.indexOf(value);
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final int expected = 5;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void identifiesThatAValueIsNotIncludedInTheArray() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST);
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final int value = 7;
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final int actual = sut.indexOf(value);
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final int expected = -1;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void aValueSmallerThanTheArraysSmallestValueIsNotIncluded() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST);
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final int value = 0;
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final int actual = sut.indexOf(value);
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final int expected = -1;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void aValueLargerThanTheArraysSmallestValueIsNotIncluded() {
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BinarySearch<Integer> sut = new BinarySearch<>(SORTED_LIST);
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final int value = 13;
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final int actual = sut.indexOf(value);
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final int expected = -1;
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assertEquals(expected, actual);
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}
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@Ignore
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@Test
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public void nothingIsIncludedInAnEmptyArray() {
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BinarySearch<Integer> sut = new BinarySearch<>(EMPTY_LIST);
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final int value = 1;
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final int actual = sut.indexOf(value);
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final int expected = -1;
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assertEquals(expected, actual);
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}
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}

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