Merge pull request #1087 from SuyashSingh01/main

Rename the file

Author: akgmage

Binary Search/Binary_search_arr.js

@@ -0,0 +1,30 @@
+/**
+ * Finds the first and last occurrence of a target value in a sorted array.
+ *
+ * @param {number[]} N - The sorted array of numbers.
+ * @param {number} T - The target value to search for.
+ * @returns {number[]} An array containing the first and last index of the target value, or [-1,-1] if not found.
+ */
+const searchRange = function(N, T) {
+    // Helper function to perform binary search on the array
+    const find = (target, arr, left=0, right=arr.length) => {
+      while (left <= right) {
+        // Calculate the middle index
+        let mid = left + right >> 1;
+        // If the middle element is less than the target, move the left pointer to mid + 1
+        if (arr[mid] < target) left = mid + 1;
+        // If the middle element is greater than or equal to the target, move the right pointer to mid - 1
+        else right = mid - 1;
+      }
+      // Return the left pointer, which will be the index of the target or the insertion point if not found
+      return left;
+    }; 
+  
+    // Find the leftmost index of the target value
+    let Tleft = find(T, N);
+    // If the target value is not found in the array, return [-1,-1]
+    if (N[Tleft] !== T) return [-1,-1];
+    // Find the rightmost index of the target value
+    return [Tleft, find(T+1, N, Tleft) - 1];
+  };
+