Java Program to Compare Binary and Sequential Search

This is a java program to compare Binary Search and Linear Search algorithms. Following class provides the time required to search an element for both the algorithms

Here is the source code of the Java Program to Compare Binary and Sequential Search. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.

//This the the java program to compare the sequential and binary search

```
import java.util.Random;
```
```
import java.util.Scanner;
```
```
 
```
```
public class Sequential_Binary_Compare 
```
```
{
```
```
    public static int N = 1000;
```

    public static int[] sequence = new int[N];

```
 
```

    public static boolean sequentialSearch(int[] sequence, int key)

```
    {
```

        for (int i = 0; i < sequence.length; i++)

```
            if (sequence[i] == key)
```
```
                return true;
```
```
        return false;
```
```
    }
```
```
 
```

    public static boolean binarySearch(int[] sequence, int key)

```
    {
```

        int low = 0, high = sequence.length - 1;

```
        while (low <= high) 
```
```
        {
```
```
            int mid = (low + high) / 2;
```
```
            if (key < sequence[mid])
```
```
                high = mid - 1;
```

            else if (key > sequence[mid])

```
                low = mid + 1;
```
```
            else
```
```
                return true;
```
```
        }
```
```
        return false;
```
```
    }
```
```
 
```

    public static void QuickSort(int left, int right)

```
    {
```
```
        if (right - left <= 0)
```
```
            return;
```
```
        else 
```
```
        {
```

            int pivot = sequence[right];

            int partition = partitionIt(left, right, pivot);

            QuickSort(left, partition - 1);

            QuickSort(partition + 1, right);

```
        }
```
```
    }
```
```
 
```

    public static int partitionIt(int left, int right, long pivot)

```
    {
```
```
        int leftPtr = left - 1;
```
```
        int rightPtr = right;
```
```
        while (true) 
```
```
        {
```

            while (sequence[++leftPtr] < pivot)

```
                ;
```

            while (rightPtr > 0 && sequence[--rightPtr] > pivot)

```
                ;
```
```
 
```
```
            if (leftPtr >= rightPtr)
```
```
                break;
```
```
            else
```

                swap(leftPtr, rightPtr);

```
        }
```
```
        swap(leftPtr, right);
```
```
        return leftPtr;
```
```
    }
```
```
 
```

    public static void swap(int dex1, int dex2)

```
    {
```
```
        int temp = sequence[dex1];
```

        sequence[dex1] = sequence[dex2];

```
        sequence[dex2] = temp;
```
```
    }
```
```
 
```

    public static void main(String args[])

```
    {
```
```
        Random random = new Random();
```
```
 
```
```
        for (int i = 0; i < N; i++)
```

            sequence[i] = Math.abs(random.nextInt(100));

```
 
```

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter the key to be searched: ");

```
        int k = sc.nextInt();
```
```
 
```
```
        System.out
```

                .println("Time taken to search key using sequential search: ");

        long startTime = System.nanoTime();

        boolean result = sequentialSearch(sequence, k);

        long endTime = System.nanoTime();

```
 
```
```
        if (result == true)
```

            System.out.println("Key found in " + (endTime - startTime)

```
                    + " nanoseconds");
```
```
        else
```

            System.out.println("Key doesn't exist, execution time "

                    + (endTime - startTime) + " nanoseconds");

```
 
```

        System.out.println("Time taken to search key using binary search: ");

```
        QuickSort(0, N - 1);
```
```
        startTime = System.nanoTime();
```

        result = sequentialSearch(sequence, k);

```
        endTime = System.nanoTime();
```
```
 
```
```
        if (result == true)
```

            System.out.println("Key found in " + (endTime - startTime)

```
                    + " nanoseconds");
```
```
        else
```

            System.out.println("Key doesn't exist, execution time "

                    + (endTime - startTime) + " nanoseconds");

```
        sc.close();
```
```
    }
```
```
}
```

Output:

$ javac Sequential_Binary_Compare.java
$ java Sequential_Binary_Compare
 
Enter the key to be searched: (N=100)
85
Time taken to search key using sequential search: 
Key found in 14696 nanoseconds
Time taken to search key using binary search: 
Key found in 6680 nanoseconds
 
Enter the key to be searched: (N=1000)
562
Time taken to search key using sequential search: 
Key doesn't exist, execution time 44422 nanoseconds
Time taken to search key using binary search: 
Key doesn't exist, execution time 43420 nanoseconds

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