List of top Computer Science Questions

Consider a directed graph \( G = (V,E) \), where \( V = \{0,1,2,\dots,100\} \) and
\[ E = \{(i,j) : 0 < j - i \leq 2, \text{ for all } i,j \in V \}. \] Suppose the adjacency list of each vertex is in decreasing order of vertex number, and depth-first search (DFS) is performed at vertex 0. The number of vertices that will be discovered after vertex 50 is:

Consider the following tables, Loan and Borrower, of a bank.

Query: \[ \pi_{\text{branch\_name}, \text{customer\_name}} (\text{Loan} \bowtie \text{Borrower}) \div \pi_{\text{branch\_name}}(\text{Loan}) \] where \( \bowtie \) denotes natural join. The number of tuples returned by the above relational algebra query is 1 (Answer in integer).

Consider the following three relations:
Car (model, year, serial, color)
Make (maker, model)
Own (owner, serial)
A tuple in Car represents a specific car of a given model, made in a given year, with a serial number and a color. A tuple in Make specifies that a maker company makes cars of a certain model. A tuple in Own specifies that an owner owns the car with a given serial number. Keys are underlined; (owner, serial) together form key for Own. (\(\bowtie\) denotes natural join)
\[ \pi_{owner} \left( Own \bowtie \sigma_{color="red"} \left( Car \bowtie \sigma_{maker="ABC"} Make \right) \right) \] Which one of the following options describes what the above expression computes?

Column-I has statements made by Shanthala; and, Column-II has responses given by Kanishk.

_________ is the positive square root of the average of squared differences of each value from the mean.

Consider the tables Admin and Transport given below:

Table: Admin

\[ \begin{array}{|c|c|c|c|} \hline \textbf{S\_id} & \textbf{S\_name} & \textbf{Address} & \textbf{S\_type} \\ \hline S001 & Sandhya & Rohini & Day Boarder \\ S002 & Vedanshi & Rohtak & Day Scholar \\ S003 & Vibhu & Raj Nagar & NULL \\ S004 & Atharva & Rampur & Day Boarder \\ \hline \end{array} \]

Table: Transport

\[ \begin{array}{|c|c|c|} \hline \textbf{S\_id} & \textbf{Bus\_no} & \textbf{Stop\_name} \\ \hline S002 & TSS10 & Sarai Kale Khan \\ S004 & TSS12 & Sainik Vihar \\ S005 & TSS10 & Kamla Nagar \\ \hline \end{array} \]

Write SQL queries for the following:

Display the student name and their stop name from the tables Admin and Transport.
Display the number of students whose S_type is not known.
Display all details of the students whose name starts with 'V'.
Display student ID and address in alphabetical order of student name, from the table Admin.