Binary Search Done At Office

src/BinaryDSA.java

@@ -0,0 +1,20 @@
+public class BinaryDSA {
+    public static int rank(int key, int[] array) {
+        return rank(key, array, 0, array.length - 1);
+    }
+
+    public static int rank(int key, int[] array, int lo, int hi) {
+        if (lo > hi) return -1;
+        int mid = lo + (hi - lo) / 2;
+        if (key < array[mid]) return rank(key, array, lo, mid - 1);
+        else if (key > array[mid]) return rank(key, array, mid + 1, hi);
+        else return mid;
+    }
+
+    public static void main(String[] args) {
+        int[] sortedArray = {10, 20, 30, 40, 50};
+        int keyToFind = 40;
+
+        System.out.println(rank(keyToFind,sortedArray));
+    }
+}

src/BinarySearch.java

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+public class BinarySearch {
+    public static int binarySearch(int[] array, int key) {
+        int low = 0;
+        int high = array.length - 1;
+
+        while (low <= high) {
+            int mid = low + (high - low) / 2;
+
+            if (array[mid] == key) {
+                return mid;
+            } else if (array[mid] < key) {
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+        }
+
+        return -1;
+    }
+
+    public static void main(String[] args) {
+        int[] sortedArray = {10, 20, 30, 40, 50};
+        int keyToFind = 40;
+
+        int result = binarySearch(sortedArray,keyToFind);
+        if (result != -1) {
+            System.out.println(keyToFind + " found at index " + result);
+        }else {
+            System.out.println(keyToFind + " not found in the array");
+        }
+    }
+}

src/UnknownOrder.java

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+public class UnknownOrder {
+    public static int binarySearch(int[] array, int key) {
+        int low = 0;
+        int high = array.length - 1;
+
+        while (low <= high) {
+            int mid = low + (high - low) / 2;
+
+            if (array[mid] == key) {
+                return mid;
+            } else if (array[mid] > array[mid + 1]) {
+                if (array[mid] > key) {
+                    low = mid + 1;
+                } else {
+                    high = mid - 1;
+                }
+            } else {
+                if (array[mid] < key) {
+                    low = mid + 1;
+                } else {
+                    high = mid - 1;
+                }
+            }
+        }
+        return -1;
+    }
+
+    public static void main(String[] args) {
+        int[] ascArray = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
+        int keyToFind1 = 40;
+
+        int result1 = binarySearch(ascArray, keyToFind1);
+        if (result1 != -1) {
+            System.out.println(keyToFind1 + " found at index " + result1);
+        } else {
+            System.out.println(keyToFind1 + " not found in the array");
+        }
+        int[] desArray = {100, 90, 80, 70, 60, 50, 40, 30, 20, 10};
+        int keyToFind2 = 50;
+
+        int result2 = binarySearch(desArray, keyToFind2);
+        if (result2 != -1) {
+            System.out.println(keyToFind2 + " found at index " + result2);
+        } else {
+            System.out.println(keyToFind2 + " not found in the array");
+        }
+
+    }
+}