Progress: Commited Exercise 1-4

Exercise_1.cs

@@ -0,0 +1,47 @@
+
+// Time Complexity
+// Best Case - O(1)
+// Average Case - O(log n)
+// Worst Case - O(log n)
+
+// Space Complexity
+// O(1)
+public class BinarySearch
+{
+    // Returns index of x if it is present in arr[l.. r], else return -1 
+    public int binarySearch(int[] arr, int l, int r, int x)
+    {
+        //Write your code here
+        while (l <= r)
+        {
+            int mid = l + (r - l) / 2;
+            if (arr[mid] == x)
+            {
+                return mid;
+            }
+            else if (arr[mid] > x)
+            {
+                r = mid - 1;
+            }
+            else
+            {
+                l = mid + 1;
+            }
+        }
+        return -1;
+    }
+
+    // Driver method to test above 
+    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, 0, n - 1, x);
+        if (result == -1)
+            Console.WriteLine("Element not present");
+        else
+            Console.WriteLine("Element found at index " + result);
+    }
+} 

Exercise_2.cs

@@ -0,0 +1,72 @@
+//Time Complexity = O(nlogn)
+//Space Complexity = O(logn)
+class QuickSort
+{
+    /* This function takes last element as pivot, 
+       places the pivot element at its correct 
+       position in sorted array, and places all 
+       smaller (smaller than pivot) to left of 
+       pivot and all greater elements to right 
+       of pivot */
+    void swap(int[] arr, int i, int j)
+    {
+        int temp = arr[i];
+        arr[i] = arr[j];
+        arr[j] = temp;
+    }
+
+    int partition(int[] arr, int low, int high)
+    {
+        //Write code here for Partition and Swap 
+        int pivot = arr[high];
+        int i = low - 1;
+        for (int j = low; j < high; j++)
+        {
+            if (arr[j] < pivot)
+            {
+                i++;
+                swap(arr, i, j);
+            }
+        }
+        swap(arr, i + 1, high);
+        return i + 1;
+    }
+    //{10, 7, 8, 9, 1, 5}; 
+    //1,5,7,8,9,10
+    /* The main function that implements QuickSort() 
+      arr[] --> Array to be sorted, 
+      low  --> Starting index, 
+      high  --> Ending index */
+    void sort(int[] arr, int low, int high)
+    {
+        // Recursively sort elements before 
+        // partition and after partition 
+        if (low < high)
+        {
+            int pivot = partition(arr, low, high);
+            sort(arr, low, pivot - 1);
+            sort(arr, pivot + 1, high);
+        }
+    }
+
+    /* A utility function to print array of size n */
+    static void printArray(int[] arr)
+    {
+        int n = arr.Length;
+        for (int i = 0; i < n; ++i)
+            Console.WriteLine(arr[i] + " ");
+    }
+
+    // Driver program 
+    public static void main(String[] args)
+    {
+        int[] arr = { 10, 7, 8, 9, 1, 5 };
+        int n = arr.Length;
+
+        QuickSort ob = new QuickSort();
+        ob.sort(arr, 0, n - 1);
+
+        Console.WriteLine("sorted array");
+        printArray(arr);
+    }
+}