java binary search code example
Example 1: binary search java
class BinarySearch {
int binarySearch(int arr[], int x)
{
int l = 0, r = arr.length - 1;
while (l <= r) {
int m = l + (r - l) / 2;
if (arr[m] == x)
return m;
if (arr[m] < x)
l = m + 1;
else
r = m - 1;
}
return -1;
}
public static void main(String args[])
{
BinarySearch ob = new BinarySearch();
int arr[] = { 2, 3, 4, 10, 40 };
int n = arr.length;
int x = 10;
int result = ob.binarySearch(arr, x);
if (result == -1)
System.out.println("Element not present");
else
System.out.println("Element found at "
+ "index " + result);
}
}
Example 2: binary search java
binary search program in java.
public class BinarySearchExample
{
public static void binarySearch(int[] arrNumbers, int start, int end, int keyElement)
{
int middle = (start + end) / 2;
while(start <= end)
{
if(arrNumbers[middle] < keyElement)
{
start = middle + 1;
}
else if(arrNumbers[middle] == keyElement)
{
System.out.println("Element found at index: " + middle);
break;
}
else
{
end = middle - 1;
}
middle = (start + end) / 2;
}
if(start > end)
{
System.out.println("Element not found!");
}
}
public static void main(String[] args)
{
int[] arrNumbers = {14,15,16,17,18};
int keyElement = 16;
int end = arrNumbers.length - 1;
binarySearch(arrNumbers, 0, end, keyElement);
}
}
Example 3: binary search java
public int runBinarySearchRecursively(
int[] sortedArray, int key, int low, int high) {
int middle = (low + high) / 2;
if (high < low) {
return -1;
}
if (key == sortedArray[middle]) {
return middle;
} else if (key < sortedArray[middle]) {
return runBinarySearchRecursively(
sortedArray, key, low, middle - 1);
} else {
return runBinarySearchRecursively(
sortedArray, key, middle + 1, high);
}
}
Example 4: binary search implementation using java collections
public static int binarySearch(List slist, T key)
public static int binarySearch(List slist, T key, Comparator c)
If key is not present, the it returns "(-(insertion point) - 1)".
The insertion point is defined as the point at which the key
would be inserted into the list.