GATE CS question library

The grammar $S\rightarrow AC\mid CB$ $C\rightarrow aCb\mid \epsilon$ $A\rightarrow aA\mid a$ $B\rightarrow Bb\mid b$ generates the language $L=\left \{ a^{i}b^{j}\mid i\neq j \right \}$. In this grammar what is the length of the derivation (number of steps starting from $S$) to generate the string $a^{l}b^{m}$ with $l\neq m$

Statement for Linked Answer Questions 76 & 77: A $3$-ary max heap is like a binary max heap, but instead of $2$ children, nodes have $3$ children. A $3$-ary heap can be represented by an array as follows: The root is stored in the first location, $a[0]$, nodes in the next level, from left to right, is stored from $a[1]$ to $a[3]$. The nodes …

Consider the diagram shown below where a number of LANs are connected by (transparent) bridges. In order to avoid packets looping through circuits in the graph, the bridges organize themselves in a spanning tree. First, the root bridge is identified as the bridge with the least serial number. Next, the root sends out (one or more) data units to enable the …

The $2^n$ vertices of a graph $G$ corresponds to all subsets of a set of size $n$, for $n \geq 6$. Two vertices of $G$ are adjacent if and only if the corresponding sets intersect in exactly two elements. The number of connected components in $G$ is:

Consider two cache organizations. First one is $32$ $kB$ $2$-way set associative with $32$ $byte$ block size, the second is of same size but direct mapped. The size of an address is $32$ $bits$ in both cases . A $2$-to-$1$ multiplexer has latency of $0.6 ns$ while a $k-$bit comparator has latency of $\frac{k}{10} ns$. The hit latency …

The $2^n$ vertices of a graph $G$ corresponds to all subsets of a set of size $n$, for $n \geq 6$. Two vertices of $G$ are adjacent if and only if the corresponding sets intersect in exactly two elements. The maximum degree of a vertex in $G$ is:

Barrier is a synchronization construct where a set of processes synchronizes globally i.e., each process in the set arrives at the barrier and waits for all others to arrive and then all processes leave the barrier. Let the number of processes in the set be three and $S$ be a binary semaphore with the usual $P$ and $V$ functions. Consider the following …

A CPU has a $32$ $KB$ direct mapped cache with $128$ byte-block size. Suppose $A$ is two dimensional array of size $512 \times512$ with elements that occupy $8-bytes$ each. Consider the following two $C$ code segments, $P1$ and $P2$. $P1$: for (i=0; i<512; i++) { for (j=0; j<512; j++) { x +=A[i] [j]; } } P2: for (i=0; i<512; i++) …

Which one of the following grammars generates the language $L=\left \{ a^{i}b^{j}\mid i\neq j \right \}$?

Consider the diagram shown below where a number of LANs are connected by (transparent) bridges. In order to avoid packets looping through circuits in the graph, the bridges organize themselves in a spanning tree. First, the root bridge is identified as the bridge with the least serial number. Next, the root sends out (one or more) data units to enable the …

A CPU has a $32 KB$ direct mapped cache with $128$ byte-block size. Suppose A is two dimensional array of size $512 \times512$ with elements that occupy $8$-bytes each. Consider the following two C code segments, $P1$ and $P2$. P1: for (i=0; i<512; i++) { for (j=0; j<512; j++) { x +=A[i] [j]; } } P2: for (i=0; i<512; i++) { for (j=0; …

Barrier is a synchronization construct where a set of processes synchronizes globally i.e., each process in the set arrives at the barrier and waits for all others to arrive and then all processes leave the barrier. Let the number of processes in the set be three and $S$ be a binary semaphore with the usual $P$ and $V$ functions. Consider the following …

Statement for Linked Answer Questions 76 & 77: A $3$-ary max heap is like a binary max heap, but instead of $2$ children, nodes have $3$ children. A $3$-ary heap can be represented by an array as follows: The root is stored in the first location, $a[0]$, nodes in the next level, from left to right, is stored from $a[1]$ to $a[3]$. The nodes …

Consider two cache organizations. First one is $32 \; \textsf{KB}\;2\text{-way}$ set associative with $32 \; \text{byte}$ block size, the second is of same size but direct mapped. The size of an address is $32\; \text{bits}$ in both cases . A $2\text{-to-}1$ multiplexer has latency of $0.6 \; \text{ns}$ while a $k\text{-bit}$ comparator has …

The $2^n$ vertices of a graph $G$ corresponds to all subsets of a set of size $n$, for $n \geq 6$. Two vertices of $G$ are adjacent if and only if the corresponding sets intersect in exactly two elements. The number of vertices of degree zero in $G$ is:

Consider the relation enrolled (student, course) in which (student, course) is the primary key, and the relation paid (student, amount) where student is the primary key. Assume no null values and no foreign keys or integrity constraints. Assume that amounts $6000, 7000, 8000, 9000$ and $10000$ were each paid by $20\%$ of the students. Consider these …

Consider the relation enrolled (student, course) in which (student, course) is the primary key, and the relation paid (student, amount) where student is the primary key. Assume no null values and no foreign keys or integrity constraints. Given the following four queries: Query1: select student from enrolled where student in (select student from paid) Query2: …

Consider the relation account (customer, balance) where the customer is a primary key and there are no null values. We would like to rank customers according to decreasing balance. The customer with the largest balance gets rank $1.$ Ties are not broke but ranks are skipped: if exactly two customers have the largest balance they each get rank $1$ and …

Consider the following snapshot of a system running $n$ processes. Process $i$ is holding $x_i$ instances of a resource $R$, $1\leq i\leq n$ . Currently, all instances of $R$ are occupied. Further, for all $i$, process $i$ has placed a request for an additional $y_i$ instances while holding the $x_i$ instances it already has. There are …

Consider three processes, all arriving at time zero, with total execution time of $10$, $20$ and $30$ units, respectively. Each process spends the first $\text{20\%}$ of execution time doing I/O, the next $\text{70\%}$ of time doing computation, and the last $\text{10\%}$ of time doing I/O again. The operating system uses a shortest remaining …