Skip to content

Added Linear Search, changed Binary search #628

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Dec 12, 2018
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 5 additions & 5 deletions src/main/java/com/search/BinarySearch.java
Original file line number Diff line number Diff line change
Expand Up @@ -8,26 +8,26 @@
* Average performance O(log n)
* Worst-case space complexity O(1)
*/
public class BinarySearch {
public final class BinarySearch{

/**
* @param array is an array where the element should be found
* @param key is an element which should be found
* @param <T> is any comparable type
* @return index of the element
*/
public <T extends Comparable<T>> int findIndex(T array[], T key) {
public static <T extends Comparable<T>> int findIndex(T array[], T key) {
return search(array, key, 0, array.length-1);
}

/**
* @param array The array to make the binary search
* @param key The number you are looking for
* @param array The array to search
* @param key The element you are looking for
* @param left The lower bound
* @param right The upper bound
* @return the location of the key
**/
private <T extends Comparable<T>> int search(T array[], T key, int left, int right){
private static <T extends Comparable<T>> int search(T array[], T key, int left, int right){
if (left > right) {
return -1; // Key not found
}
Expand Down
35 changes: 35 additions & 0 deletions src/main/java/com/search/LinearSearch.java
Original file line number Diff line number Diff line change
@@ -0,0 +1,35 @@
package src.main.java.com.search;

/**
* Linear search is an algorithm which finds the position of a target value within an array (Usually unsorted)
*
* Worst-case performance O(n)
* Best-case performance O(1)
* Average performance O(n)
* Worst-case space complexity O(1)
*/
public final class LinearSearch {
/**
* @param array is an array where the element should be found
* @param key is an element which should be found
* @param <T> is any comparable type
* @return index of the element
*/
public static <T extends Comparable<T>> int findIndex(T array[], T key) {
return search(array, key);
}

/**
* @param array The array to search
* @param key The element you are looking for
* @return the location of the key or -1 if the element is not found
**/
private static <T extends Comparable<T>> int search(T array[], T key){
for(int i = 0; i < array.length;i++) {
if (array[i].compareTo(key) == 0){
return i;
}
}
return -1;
}
}
19 changes: 10 additions & 9 deletions src/test/java/com/search/BinarySearchTest.java
Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,18 @@ public class BinarySearchTest {

@Test
public void testBinarySearch() {
BinarySearch binarySearch = new BinarySearch();

Integer[] arr1 = {1,2,3,4,5};
Assert.assertEquals("Incorrect index", 2, binarySearch.findIndex(arr1,3));
Assert.assertEquals("Incorrect index", 0, binarySearch.findIndex(arr1,1));
Assert.assertEquals("Incorrect index", -1, binarySearch.findIndex(arr1,8));
Assert.assertEquals("Incorrect index", -1, binarySearch.findIndex(arr1,-2));
Assert.assertEquals("Incorrect index", 2, BinarySearch.findIndex(arr1,3));
Assert.assertEquals("Incorrect index", 0, BinarySearch.findIndex(arr1,1));
Assert.assertEquals("Incorrect index", -1, BinarySearch.findIndex(arr1,8));
Assert.assertEquals("Incorrect index", -1, BinarySearch.findIndex(arr1,-2));

String[] arr2 = {"A", "B", "C", "D"};
Assert.assertEquals("Incorrect index", 2, binarySearch.findIndex(arr2,"C"));
Assert.assertEquals("Incorrect index", 1, binarySearch.findIndex(arr2,"B"));
Assert.assertEquals("Incorrect index", -1, binarySearch.findIndex(arr2,"F"));
Assert.assertEquals("Incorrect index", 2, BinarySearch.findIndex(arr2,"C"));
Assert.assertEquals("Incorrect index", 1, BinarySearch.findIndex(arr2,"B"));
Assert.assertEquals("Incorrect index", -1, BinarySearch.findIndex(arr2,"F"));

String[] arr3 = {};
Assert.assertEquals("Incorrect index", -1, BinarySearch.findIndex(arr3, ""));
}
}
26 changes: 26 additions & 0 deletions src/test/java/com/search/LinearSearchTest.java
Original file line number Diff line number Diff line change
@@ -0,0 +1,26 @@
package src.test.java.com.search;

import org.junit.Assert;
import org.junit.Test;
import src.main.java.com.search.LinearSearch;

public class LinearSearchTest {
@Test
public void testLinearSearch() {

Integer[] arr1 = {1,2,3,4,5};
Assert.assertEquals("Incorrect index", 2, LinearSearch.findIndex(arr1,3));
Assert.assertEquals("Incorrect index", 0, LinearSearch.findIndex(arr1,1));
Assert.assertEquals("Incorrect index", -1, LinearSearch.findIndex(arr1,8));
Assert.assertEquals("Incorrect index", -1, LinearSearch.findIndex(arr1,-2));

String[] arr2 = {"A", "B", "C", "D"};
Assert.assertEquals("Incorrect index", 2, LinearSearch.findIndex(arr2,"C"));
Assert.assertEquals("Incorrect index", 1, LinearSearch.findIndex(arr2,"B"));
Assert.assertEquals("Incorrect index", -1, LinearSearch.findIndex(arr2,"F"));

String[] arr3 = {};
Assert.assertEquals("Incorrect index", -1, LinearSearch.findIndex(arr3, ""));

}
}