iSharkFly-Docs
/
java-tutorials
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Checking if an array is sorted in java (#7273) 

* SortedArrayChecker

* add recursivity method with custom object

* change test names
This commit is contained in:
Carlos Cano 2019-07-11 19:00:34 +02:00 committed by maibin
parent 4518645a1f
commit fc260052b7
3 changed files with 159 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
core-java-modules/core-java-arrays/src/main/java/com/baeldung/array/SortedArrayChecker.java Normal file
View File

@ -0,0 +1,71 @@
package com.baeldung.array;
import com.baeldung.arraycopy.model.Employee;
public class SortedArrayChecker {
boolean isSorted(int[] array, int length) {
if (array == null || length < 2)
return true;
if (array[length - 2] > array[length - 1])
return false;
return isSorted(array, length - 1);
}
boolean isSorted(int[] array) {
for (int i = 0; i < array.length - 1; i++) {
if (array[i] > array[i + 1])
return false;
}
return true;
}
boolean isSorted(String[] array, int length) {
if (array == null || length < 2)
return true;
if (array[length - 2].compareTo(array[length - 1]) > 0)
return false;
return isSorted(array, length - 1);
}
boolean isSorted(String[] array) {
for (int i = 0; i < array.length - 1; ++i) {
if (array[i].compareTo(array[i + 1]) > 0)
return false;
}
return true;
}
boolean isSortedByName(Employee[] array) {
for (int i = 0; i < array.length - 1; ++i) {
if (array[i].getName().compareTo(array[i + 1].getName()) > 0)
return false;
}
return true;
}
boolean isSortedByAge(Employee[] array) {
for (int i = 0; i < array.length - 1; ++i) {
if (array[i].getAge() > (array[i + 1].getAge()))
return false;
}
return true;
}
boolean isSortedByAge(Employee[] array, int length) {
if (array == null || length < 2)
return true;
if (array[length - 2].getAge() > array[length - 1].getAge())
return false;
return isSortedByAge(array, length - 1);
}
}

15
core-java-modules/core-java-arrays/src/main/java/com/baeldung/arraycopy/model/Employee.java
View File

@ -6,6 +6,7 @@ public class Employee implements Serializable {
private static final long serialVersionUID = -2454619097207585825L;
private int id;
private String name;
private int age;
public Employee() {
}
@ -15,10 +16,24 @@ public class Employee implements Serializable {
this.name = name;
}
public Employee(int id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}
public int getAge() {
return age;
}
public int getId() {
return id;
}
public void setAge(int age) {
this.age = age;
}
public void setId(int id) {
this.id = id;
}

73
core-java-modules/core-java-arrays/src/test/java/com/baeldung/array/SortedArrayCheckerUnitTest.java Normal file
View File

@ -0,0 +1,73 @@
package com.baeldung.array;
import com.baeldung.arraycopy.model.Employee;
import org.junit.Before;
import org.junit.Test;
import static org.assertj.core.api.Assertions.assertThat;
class SortedArrayCheckerUnitTest {
private static final int[] INTEGER_SORTED = {1, 3, 5, 7, 9};
private static final int[] INTEGER_NOT_SORTED = {1, 3, 11, 7};
private static final String[] STRING_SORTED = {"abc", "cde", "fgh"};
private static final String[] STRING_NOT_SORTED = {"abc", "fgh", "cde", "ijk"};
private final Employee[] EMPLOYEES_SORTED_BY_NAME = {
new Employee(1, "Carlos", 26),
new Employee(2, "Daniel", 31),
new Employee(3, "Marta", 27)};
private final Employee[] EMPLOYEES_NOT_SORTED_BY_NAME = {
new Employee(1, "Daniel", 31),
new Employee(2, "Carlos", 26),
new Employee(3, "Marta", 27)};
private final Employee[] EMPLOYEES_SORTED_BY_AGE = {
new Employee(1, "Carlos", 26),
new Employee(2, "Marta", 27),
new Employee(3, "Daniel", 31)};
private final Employee[] EMPLOYEES_NOT_SORTED_BY_AGE = {
new Employee(1, "Marta", 27),
new Employee(2, "Carlos", 26),
new Employee(3, "Daniel", 31)};
private SortedArrayChecker sortedArrayChecker;
@Before
public void setup() {
sortedArrayChecker = new SortedArrayChecker();
}
@Test
public void givenIntegerArray_thenReturnIfItIsSortedOrNot() {
assertThat(sortedArrayChecker.isSorted(INTEGER_SORTED)).isEqualTo(true);
assertThat(sortedArrayChecker.isSorted(INTEGER_NOT_SORTED)).isEqualTo(false);
assertThat(sortedArrayChecker.isSorted(INTEGER_SORTED, INTEGER_SORTED.length)).isEqualTo(true);
assertThat(sortedArrayChecker.isSorted(INTEGER_NOT_SORTED, INTEGER_NOT_SORTED.length)).isEqualTo(false);
}
@Test
public void givenStringArray_thenReturnIfItIsSortedOrNot() {
assertThat(sortedArrayChecker.isSorted(STRING_SORTED)).isEqualTo(true);
assertThat(sortedArrayChecker.isSorted(STRING_NOT_SORTED)).isEqualTo(false);
assertThat(sortedArrayChecker.isSorted(STRING_SORTED, STRING_SORTED.length)).isEqualTo(true);
assertThat(sortedArrayChecker.isSorted(STRING_NOT_SORTED, STRING_NOT_SORTED.length)).isEqualTo(false);
}
@Test
public void givenEmployeeArray_thenReturnIfItIsSortedOrNot() {
assertThat(sortedArrayChecker.isSortedByName(EMPLOYEES_SORTED_BY_NAME)).isEqualTo(true);
assertThat(sortedArrayChecker.isSortedByName(EMPLOYEES_NOT_SORTED_BY_NAME)).isEqualTo(false);
assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_SORTED_BY_AGE)).isEqualTo(true);
assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_NOT_SORTED_BY_AGE)).isEqualTo(false);
assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_SORTED_BY_AGE, EMPLOYEES_SORTED_BY_AGE.length)).isEqualTo(true);
assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_NOT_SORTED_BY_AGE, EMPLOYEES_NOT_SORTED_BY_AGE.length)).isEqualTo(false);
}
}