add readme

CodingTutorialC++/README.md

@@ -45,6 +45,18 @@ This file contains a program that demonstrates the use of classes and objects in
 
 This file contains a program that demonstrates the use of structures in C++. It includes examples of defining structures, creating structure variables, and accessing structure members.
 
+### [different_arrays.cpp](./different_arrays.cpp)
+
+This file contains a program that demonstrates the use of different types of arrays in C++. It includes examples of C++ default array, std::array, dynamically allocated array and std::vector.
+
+### [vector.cpp](./vector.cpp)
+
+This file contains a program that demonstrates the use of std::vector in C++. It includes examples of creating vectors, adding elements to vectors, accessing vector elements, and different vector built-in functions.
+
+### [Sort_index.cpp](./Sort_index.cpp)
+
+This file contains a program that demonstrates how to sort an array and get the index of the sorted array in C++. It includes examples of using std::sort and std::vector.
+
 ```bash
 make pi
 ./pi 4 This will build `pi.cpp` and run the resulting `pi` executable with 4 threads.