GATE CS question library

Consider the following languages: $L_{1}=\left\{a^{n}b^{m}c^{n+m}:m, n\geq 1\right\}$ $L_{2}=\left\{a^{n}b^{n}c^{2n} :n\geq 1\right\}$ Which one of the following is TRUE?

A binary relation $R$ on $\mathbb{N} \times \mathbb{N}$ is defined as follows: $(a, b) R(c, d)$ if $a \leq c$ or $b \leq d$. Consider the following propositions: $P:$ $R$ is reflexive. $Q:$ $R$ is transitive. Which one of the following statements is TRUE?

Consider the following program: int f (int * p, int n) { if (n <= 1) return 0; else return max (f (p+1, n-1), p[0] - p[1]); } int main () { int a[] = {3, 5, 2, 6, 4}; printf(" %d", f(a, 5)); } Note: $\max (x, y)$ returns the maximum of $x$ and $y$. The value printed by this program is ________.

Consider a processor with $64$ registers and an instruction set of size twelve. Each instruction has five distinct fields, namely, opcode, two source register identifiers, one destination register identifier, and twelve-bit immediate value. Each instruction must be stored in memory in a byte-aligned fashion. If a program has $100$ instructions, the …

Consider the following two-process synchronization solution. …

A student wrote two context-free grammars G1 and G2 for generating a single C-like array declaration. The dimension of the array is at least one. For example, int a[10] [3]; The grammars use D as the start symbol, and use six terminal symbols int ; id [ ] num. …

Consider the following New-order strategy for traversing a binary tree: Visit the root; Visit the right subtree using New-order; Visit the left subtree using New-order; The New-order traversal of the expression tree corresponding to the reverse polish expression 3 4 * 5 - 2 ^ 6 7 * 1 + - is given by:

Consider the following languages. $L_{1} = \left\{\left\langle M \right\rangle \mid M \text{ takes at least 2016 steps on some input} \right\}$, $L_{2} = \left\{\left\langle M \right\rangle \mid M \text{ takes at least 2016 steps on all inputs} \right\}$ and $L_{3} = \left\{\left\langle M \right\rangle \mid M \ \text{accepts }\epsilon\right\}$, where …

Consider a set $U$ of $23$ different compounds in a chemistry lab. There is a subset $S$ of $U$ of $9$ compounds, each of which reacts with exactly $3$ compounds of $U$. Consider the following statements: Each compound in U \ S reacts with an odd number of compounds. At least one compound in U \ S reacts with an odd number of compounds. Each …

Which one of the following grammars is free from left recursion?

For the $\text{IEEE 802.11 MAC}$ protocol for wireless communication, which of the following statements is/are TRUE? At least three non-overlapping channels are available for transmissions. The RTS-CTS mechanism is used for collision detection. Unicast frames are ACKed.

A file system uses an in-memory cache to cache disk blocks. The miss rate of the cache is shown in the figure. The latency to read a block from the cache is $1$ ms and to read a block from the disk is $10$ ms. Assume that the cost of checking whether a block exists in the cache is negligible. Available cache sizes are in multiples of $10$ MB. The …

Consider the following two statements: If all states of an NFA are accepting states then the language accepted by the NFA is $\Sigma_{}^{*}$. There exists a regular language $A$ such that for all languages $B$, $A \cap B$ is regular. Which one of the following is CORRECT?

Consider the following database schedule with two transactions $T_{1}$ and $T_{2}$. $S= r_{2}\left(X\right); r_{1}\left(X\right); r_{2} \left(Y\right); w_{1} \left(X\right); r_{1} \left(Y\right); w_{2} \left(X\right); a_{1}; a_{2}$ Where $r_{i} (Z)$ denotes a read operation by transaction $T_{i}$ on a variable $Z$, $w_{i}(Z)$ denotes a write …

A network has a data transmission bandwidth of $20 \times 10^{6}$ bits per second. It uses CSMA/CD in the MAC layer. The maximum signal propagation time from one node to another node is $40$ microseconds. The minimum size of a frame in the network is __________ bytes.

The value of the expression $13^{99}\pmod{17}$ in the range $0$ to $16$, is ________.

Let $A_{1}, A_{2}, A_{3}$ and $A_{4}$ be four matrices of dimensions $10 \times 5, 5 \times 20, 20 \times 10$ and $10 \times 5$, respectively. The minimum number of scalar multiplications required to find the product $A_{1}A_{2}A_{3}A_{4}$ using the basic matrix multiplication method is _________.

The number of ways in which the numbers $1, 2, 3, 4, 5, 6, 7$ can be inserted in an empty binary search tree, such that the resulting tree has height $6$, is _________. Note: The height of a tree with a single node is $0$.

A complete binary min-heap is made by including each integer in $[1, 1023]$ exactly once. The depth of a node in the heap is the length of the path from the root of the heap to that node. Thus, the root is at depth $0$. The maximum depth at which integer $9$ can appear is _________.

Consider a $3 \ \text{GHz}$ (gigahertz) processor with a three stage pipeline and stage latencies $\large\tau_1,\tau_2$ and $\large\tau_3$ such that $\large\tau_1 =\dfrac{3 \tau_2}{4}=2\tau_3$. If the longest pipeline stage is split into two pipeline stages of equal latency , the new frequency is __________ $\text{GHz}$, ignoring delays in the …