* Data Structures and Algorithms Introduction* –

Data Structure is a way of collecting and organising data in such a way that we can perform operations on these data in an effective way. Data Structures is about rendering data elements in terms of some relationship, for better organization and storage. For example, we have data player’s name “Virat” and age 26. Here “Virat” is of **String** data type and 26 is of **integer** data type.

We can organize this data as a record like **Player** record. Now we can collect and store player’s records in a file or database as a data structure. For example: “Dhoni” 30, “Gambhir” 31, “Sehwag” 33

In simple language, Data Structures are structures programmed to store ordered data, so that various operations can be performed on it easily.

**Characteristics of a Data Structure –**

**Correctness**− Data structure implementation should implement its interface correctly.**Time Complexity**− Running time or the execution time of operations of data structure must be as small as possible.**Space Complexity**− Memory usage of a data structure operation should be as little as possible.

**Types of Data Structure – **

As we discussed above, anything that can store data can be called as a data strucure, hence Integer, Float, Boolean, Char etc, all are data structures. They are known as **Primitive Data Structures**.

Then we also have some complex Data Structures, which are used to store large and connected data. Some example of **Abstract Data Structure** are :

- Linked List
- Tree
- Graph
- Stack, Queue etc.

All these data structures allow us to perform different operations on data. We select these data structures based on which type of operation is required. We will look into these data structures in more details in our later lessons.

An algorithm is a finite set of instructions or logic, written in order, to accomplish a certain predefined task. Algorithm is not the complete code or program, it is just the core logic(solution) of a problem, which can be expressed either as an informal high level description as **pseudocode** or using a **flowchart**.

**Algorithm** –

An algorithm is said to be efficient and fast, if it takes less time to execute and consumes less memory space. The performance of an algorithm is measured on the basis of following properties :

- Time Complexity
- Space Complexity