The video discusses the top six coding interview concepts that are commonly tested, as per the speaker's experience.
1. **Heap**: A data structure that is used to efficiently extract the minimum or maximum value, or to find the top k values. Heaps can be built in O(n) time if all values are available at the start, but if values are added one by one, it takes O(n log n) time.
2. **Sliding Window**: An algorithm that uses two pointers to iterate through an array, reducing the time complexity from O(n^2) to O(n). It is often used in problems where a subarray of a certain size needs to be found.
3. **Binary Search**: An efficient algorithm used to search for a value in a sorted array or list. It works by repeatedly dividing the search space in half, making it a lot more efficient than linear search.
4. **Depth First Search (DFS) and Breadth First Search (BFS)**: These are common algorithms used in coding interviews, as they can be applied to a variety of data structures, including trees and graphs. They form the building blocks for more complex algorithms like Dijkstra's algorithm, Kruskal's algorithm, and Prim's algorithm.
5. **Recursion**: This is a fundamental concept in programming that is used in many areas, including backtracking and dynamic programming. It is important to understand the base case, the recursive step, and how recursion interacts with the call stack.
6. **Hashmaps**: These are data structures that allow for efficient addition, removal, and searching of values. They are commonly used in coding interviews to solve problems efficiently. Every operation on a hashmap can be done in constant time on average.
The speaker emphasizes that while advanced algorithms like dynamic programming exist, they are not as commonly asked in interviews. Instead, understanding and mastering the above six concepts will prepare candidates well for most coding interviews.
1. The text is a tutorial on the top six coding interview concepts that the speaker believes are most common based on their experience.
2. These concepts are:
- Heap data structure: Heaps are a very common data structure that comes up in coding interviews. They are used to get the minimum or maximum value, or to solve problems like getting the top k values.
- Sliding window: This is a standard algorithm where two pointers are used to iterate through an array. It's a very efficient algorithm that can solve many problems with a time complexity of O(n).
- Binary search: This algorithm is used to find a value in an array. It's more efficient than a linear search with a time complexity of O(log n).
- Depth-first search (DFS) and breadth-first search (BFS): These are common algorithms used in coding interviews. They can be applied to trees and general graphs. DFS and BFS are the building blocks for more complex algorithms.
- Recursion: This is a fundamental concept in computer science and is used in many places, including graphs, backtracking, and dynamic programming. Understanding recursion is crucial for coding interviews.
- Hashmaps: Hashmaps are a simple but very common data structure used in coding interviews. They allow for efficient operations like adding, removing, and searching for values.
3. The speaker suggests that candidates should focus on understanding these six concepts before moving on to more complex topics like dynamic programming.