GATE CS question library

A processor uses $\text{2-level}$ page tables for virtual to physical address translation. Page tables for both levels are stored in the main memory. Virtual and physical addresses are both $32$ bits wide. The memory is byte addressable. For virtual to physical address translation, the $10$ most significant bits of the virtual address are used as index …

Consider the following assembly language program for a hypothetical processor $A, B,$ and $C$ are $8$ bit registers. The meanings of various instructions are shown as comments. MOV B, #0 ; $B \leftarrow 0$ MOV C, #8 ; $C \leftarrow 8$ Z: CMP C, #0 ; compare C with 0 JZ X ; jump to X if zero flag is set SUB C, #1 ; $C \gets C-1$ RRC A, #1 ; right …

In a permutation $a_1\ldots a_n$, of $n$ distinct integers, an inversion is a pair $(a_i, a_j)$ such that $i < j$ and $a_i > a_j.$ What would be the worst case time complexity of the Insertion Sort algorithm, if the inputs are restricted to permutations of $1. . . n$ with at most $n$ inversions?

The following program fragment is written in a programming language that allows global variables and does not allow nested declarations of functions. global int i=100, j=5; void P(x) { int i=10; print(x+10); i=200; j=20; print (x); } main() {P(i+j);} If the programming language uses dynamic scoping and call by name parameter passing mechanism, the values …

Suppose we want to synchronize two concurrent processes $P$ and $Q$ using binary semaphores $S$ and $T$. The code for the processes $P$ and $Q$ is shown below. …

Consider the following circuit composed of XOR gates and non-inverting buffers. The non-inverting buffers have delays $\delta_1 = 2 ns$ and $\delta_2 = 4 ns$ as shown in the figure. Both XOR gates and all wires have zero delays. Assume that all gate inputs, outputs, and wires are stable at logic level $0$ at time $0$. If the following waveform is …

In a min-heap with $n$ elements with the smallest element at the root, the $7^{th}$ smallest element can be found in time

Consider the function $f$ defined below. struct item { int data; struct item * next; }; int f(struct item *p) { return ((p == NULL) || (p->next == NULL)|| ((p->data <= p ->next -> data) && f(p->next))); } For a given linked list $p$, the function $f$ returns $1$ if and only if

Consider the C program shown below: #include<stdio.h> #define print(x) printf("%d", x) int x; void Q(int z) { z+=x; print(z); } void P(int *y) { int x = *y + 2; Q(x); *y = x - 1; print(x); } main(void) { x = 5; P(&x); print(x); } The output of this program is:

In the following $C$ program fragment, $j$, $k$, $n$ and TwoLog_n are integer variables, and $A$ is an array of integers. The variable $n$ is initialized to an integer $\geqslant 3$, and TwoLog_n is initialized to the value of $2^*\lceil \log_2(n) \rceil$ for (k = 3; k <= n; k++) A[k] = 0; for (k = 2; k <= TwoLog_n; k++) for (j = k+1; j …

Consider three data items $D1, D2,$ and $D3,$ and the following execution schedule of transactions $T1, T2,$ and $T3.$ In the diagram, $R(D)$ and $W(D)$ denote the actions reading and writing the data item $D$ respectively. …

Consider the set of relations shown below and the SQL query that follows. Students: (Roll_number, Name, Date_of_birth) Courses: (Course_number, Course_name, Instructor) Grades: (Roll_number, Course_number, Grade) Select distinct Name from Students, Courses, Grades where Students.Roll_number=Grades.Roll_number and Courses.Instructor = 'Korth' and …

Consider the following functional dependencies in a database. …

Host $A$ is sending data to host $B$ over a full duplex link. $A$ and $B$ are using the sliding window protocol for flow control. The send and receive window sizes are $5$ packets each. Data packets (sent only from $A$ to $B$) are all $1000$ bytes long and the transmission time for such a packet is $50$ $μs$. Acknowledgment packets (sent …

A $2$ $km$ long broadcast LAN has $10^7$ bps bandwidth and uses CSMA/CD. The signal travels along the wire at $2 \times 10^8$ m/s. What is the minimum packet size that can be used on this network?

The subnet mask for a particular network is $255.255.31.0.$ Which of the following pairs of $\text{IP}$ addresses could belong to this network?

Suppose we want to synchronize two concurrent processes $P$ and $Q$ using binary semaphores $S$ and $T$. The code for the processes $P$ and $Q$ is shown below. Process P: Process Q: while(1){ W: print '0'; print '0'; X: } while(1){ Y: print '1'; print '1'; Z: } Synchronization statements can be inserted only at points $W, X, Y,$ and $Z$ Which …

A uni-processor computer system only has two processes, both of which alternate $10$ $\text{ms}$ CPU bursts with $90$ $\text{ms}$ I/O bursts. Both the processes were created at nearly the same time. The I/O of both processes can proceed in parallel. Which of the following scheduling strategies will result in the least CPU utilization (over a long …

Which of the following is NOT an advantage of using shared, dynamically linked libraries as opposed to using statistically linked libraries?

Consider the following class definitions in a hypothetical Object Oriented language that supports inheritance and uses dynamic binding. The language should not be assumed to be either Java or C++, though the syntax is similar. Class P { Class Q subclass of P { void f(int i) { void f(int i) { print(i); print(2*i); } } } } Now consider the following program …