Add binary search

Author: mcleber

src/binary_search.cpp

@@ -0,0 +1,98 @@
+#include <iostream>
+#include <algorithm> // For std::sort
+
+void printArray(const int *array, int size);
+int binarySearch(const int *array, int size, int value);
+
+int main()
+{
+    // Initialize an array with 10 integer values
+    int array[10] = {1, 45, 65, 22, 76, 55, 88, 81, 99, 96};
+    int valueToFind;
+
+    // Sort the array before performing binary search
+    std::sort(array, array + 10);
+
+    // Print the sorted contents of the array
+    printArray(array, 10);
+
+    // Ask the user to enter a number they want to find
+    std::cout << "Enter the number you want to find: ";
+    std::cin >> valueToFind;
+
+    // Use binary search to search for the value in the sorted array
+    int index = binarySearch(array, 10, valueToFind);
+
+    // Check if the value was found and display the result
+    if (index != -1)
+    {
+        std::cout << "The value was found at position: " << index << std::endl;
+    }
+    else
+    {
+        std::cout << "The value was not found in the array.\n";
+    }
+
+    return 0;
+}
+
+/**
+ * @brief Prints the elements of an integer array (vector).
+ *
+ * This function takes an array and its size as parameters, and prints all the
+ * elements of the array, separating them with a dash (" - ").
+ *
+ * @param array The integer array to be printed.
+ * @param size The size of the array.
+ */
+
+void printArray(const int *array, int size)
+{
+    std::cout << "Array: ";
+    for (int i = 0; i < size; i++)
+    {
+        std::cout << array[i] << " - "; // Print each element followed by " - "
+    }
+    std::cout << std::endl;
+}
+
+/**
+ * @brief Performs a binary search on a sorted array.
+ *
+ * This function implements the binary search algorithm, which efficiently finds
+ * an element in a sorted array by repeatedly dividing the search interval in half.
+ *
+ * @param array The sorted array to search.
+ * @param size The size of the array.
+ * @param value The value to search for in the array.
+ * @return The index of the element if found, or -1 if the element is not found.
+ */
+int binarySearch(const int *array, int size, int value)
+{
+    int left{0};
+    int right{size - 1};
+
+    while (left <= right)
+    {
+        int mid = left + (right - left) / 2; // Calculate middle index
+
+        // Check if the value is at the middle
+        if (array[mid] == value)
+        {
+            return mid; // Value found, return its index
+        }
+
+        // If the value is greater, ignore the left half
+        if (array[mid] < value)
+        {
+            left = mid + 1;
+        }
+        // If the value is smaller, ignore the right half
+        else
+        {
+            right = mid - 1;
+        }
+    }
+
+    return -1; // Value not found
+}