What is the primary goal of SQL injection attacks?
- Code execution
- Data manipulation
- Server overload
- Unauthorized access to a database
SQL injection attacks aim to gain unauthorized access to a database by exploiting vulnerabilities in the input handling of SQL queries. Attackers try to manipulate or extract sensitive data by injecting malicious SQL code.
A security audit requires tracking unauthorized access attempts in a CodeIgniter application. This can be done by analyzing the ________.
- Access Logs
- CSRF Token Usage
- Error Logs
- Session Data
Analyzing the Access Logs is crucial for tracking unauthorized access attempts during a security audit. Access Logs provide information about requests made to the application, helping identify potential security threats.
What is the primary purpose of error handling in CodeIgniter?
- Displaying errors to the user
- Handling errors gracefully
- Ignoring errors completely
- Logging errors for analysis
Error handling in CodeIgniter is primarily about dealing with errors in a way that doesn't disrupt the user experience. This involves handling errors gracefully to provide useful information without revealing sensitive details.
Which method in the Email Class is used to send HTML formatted emails?
- send()
- set_format()
- set_html()
- set_mailtype()
The set_mailtype() method in the Email Class is used to specify the email format. Setting it to 'html' enables the sending of HTML-formatted emails. This is essential when you want to include styled content in your emails.
How does radix sort differ from comparison-based sorting algorithms like bubble sort and merge sort?
- Radix sort is less efficient than bubble sort
- Radix sort only works with integers
- Radix sort uses comparison operations
- Radix sort uses the actual values of the elements
Radix sort differs from comparison-based sorting algorithms by considering the actual values of the elements rather than relying on comparisons. It operates based on the structure of the keys rather than their values.
What is the time complexity of BFS when implemented on an adjacency list representation of a graph?
- O(E)
- O(V * E)
- O(V + E)
- O(V)
The time complexity of BFS on an adjacency list representation of a graph is O(V + E), where V is the number of vertices and E is the number of edges. BFS visits each vertex and edge once, making it a linear-time algorithm with respect to the size of the graph.
What are the main applications of Dijkstra's algorithm in real-world scenarios?
- Shortest path in network routing
- Image processing
- Load balancing in distributed systems
- Genetic algorithms
Dijkstra's algorithm is widely used in network routing to find the shortest path. It's applied in scenarios like computer networks, transportation systems, and logistics for efficient pathfinding. Other options, such as image processing or genetic algorithms, are not primary applications of Dijkstra's algorithm.
Explain the concept of hash table resizing and its importance in maintaining performance.
- Hash table resizing involves increasing or decreasing the size of the hash table and is crucial for maintaining performance.
- Hash table resizing is done to reduce memory usage.
- Hash table resizing is not necessary for performance.
- Hash table resizing is only done when the load factor is 1.
Hash table resizing is essential to maintain a low load factor, ensuring efficient performance. When the load factor is too high, resizing involves creating a larger table and rehashing existing elements to distribute them more evenly, preventing excessive collisions. Conversely, when the load factor is too low, resizing to a smaller table can conserve memory.
The time complexity of the dynamic programming approach for finding the longest common subsequence is _______.
- O(2^n)
- O(n log n)
- O(n^2)
- O(nm)
The time complexity of the dynamic programming approach for finding the Longest Common Subsequence (LCS) is O(n^2), where 'n' and 'm' are the lengths of the input strings. This is achieved by filling up a 2D table in a bottom-up manner.
Suppose you have an array where all elements are identical. Discuss the behavior of Quick Sort in this scenario and suggest a modification to improve its performance.
- Quick Sort would efficiently partition the array but inefficiently sort it
- Quick Sort would exhibit poor performance in this scenario
- Quick Sort would sort the array with average efficiency
- Quick Sort would terminate immediately due to a sorted array
Quick Sort's behavior in an array with identical elements is problematic as it often results in uneven partitions, leading to poor performance. To improve performance, a modification could involve implementing a pivot selection strategy that chooses a pivot intelligently, such as median-of-three or random pivot selection, to mitigate the issue of uneven partitions.