Add the initial EN translation for C++ code (#1346)

en/codes/cpp/chapter_searching/linear_search.cpp

@@ -0,0 +1,49 @@
+/**
+ * File: linear_search.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Linear search (array) */
+int linearSearchArray(vector<int> &nums, int target) {
+    // Traverse array
+    for (int i = 0; i < nums.size(); i++) {
+        // Found the target element, thus return its index
+        if (nums[i] == target)
+            return i;
+    }
+    // Did not find the target element, thus return -1
+    return -1;
+}
+
+/* Linear search (linked list) */
+ListNode *linearSearchLinkedList(ListNode *head, int target) {
+    // Traverse the list
+    while (head != nullptr) {
+        // Found the target node, return it
+        if (head->val == target)
+            return head;
+        head = head->next;
+    }
+    // If the target node is not found, return nullptr
+    return nullptr;
+}
+
+/* Driver Code */
+int main() {
+    int target = 3;
+
+    /* Perform linear search in array */
+    vector<int> nums = {1, 5, 3, 2, 4, 7, 5, 9, 10, 8};
+    int index = linearSearchArray(nums, target);
+    cout << "The index of target element 3 is " << index << endl;
+
+    /* Perform linear search in linked list */
+    ListNode *head = vecToLinkedList(nums);
+    ListNode *node = linearSearchLinkedList(head, target);
+    cout << "The corresponding node object for target node value 3 is " << node << endl;
+
+    return 0;
+}