ASSIGN 2 VALUES USING -> OPERATOR AND PRINT SUM USING CAT() IN R LANGUAGE
Tuesday, January 6, 2026
ASSIGN 2 VALUES USING <- OPERATOR AND PRINT SUM OF TWO VALUES IN R LANGUAGE
ASSIGN 2 VALUES USING <- OPERATOR AND PRINT SUM OF TWO VALUES IN R LANGUAGE
Tuesday, December 2, 2025
Realloc
#include <stdio.h>
#include <stdlib.h>
int main() {
int *ptr;
int n = 5,m;
printf("Enter number of values:\n");
scanf("%d",&n);
ptr = (int *)calloc(n, sizeof(int));
if (ptr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("\n");
for (int i = 0; i < n; i++) {
ptr[i] = i *10+10;
}
printf("After assigning values:\n");
for (int i = 0; i <n ; i++) {
printf("%d ", ptr[i]);
}
printf("\n");
printf(" values with extra index:\n");
for (int i = 0; i <n +5; i++) {
printf("%d ", ptr[i]);
}
m=n+5;
ptr = (int *)calloc(m, sizeof(int));
printf("\n");
printf("After realloc values:\n");
for (int i = 0; i <m ; i++) {
printf("%d ", ptr[i]);
}
return 0;
}
Calloc and free
#include <stdio.h>
#include <stdlib.h>
int main() {
int *ptr;
int n = 5;
printf("Enter number of values:\n");
scanf("%d",&n);
ptr = (int *)calloc(n, sizeof(int));
if (ptr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("\n");
for (int i = 0; i < n; i++) {
ptr[i] = i *10+10;
}
printf("After assigning values:\n");
for (int i = 0; i <n ; i++) {
printf("%d ", ptr[i]);
}
printf("\n");
printf(" values with extra index:\n");
for (int i = 0; i <n +5; i++) {
printf("%d ", ptr[i]);
}
free(ptr);
printf("\n");
printf("After free values:\n");
for (int i = 0; i <n ; i++) {
printf("%d ", ptr[i]);
}
return 0;
}
calloc 2
//calloc
#include <stdio.h>
#include <stdlib.h>
int main() {
int *ptr;
int n = 5;
printf("Enter number of values:\n");
scanf("%d",&n);
ptr = (int *)calloc(n, sizeof(int));
if (ptr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("\n");
for (int i = 0; i < n; i++) {
ptr[i] = i *10+10;
}
printf("After assigning values:\n");
for (int i = 0; i < 10; i++) {
printf("%d ", ptr[i]);
}
printf("\n");
free(ptr);
ptr = NULL;
return 0;
}
Tuesday, November 25, 2025
Calloc
//calloc
#include <stdio.h>
#include <stdlib.h>
int main() {
int *ptr;
int n = 5;
printf("Enter number of values:\n");
scanf("%d",&n);
ptr = (int *)calloc(n, sizeof(int));
if (ptr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("\n");
for (int i = 0; i < n; i++) {
ptr[i] = i *10+10;
}
printf("After assigning values:\n");
for (int i = 0; i < n; i++) {
printf("%d ", ptr[i]);
}
printf("\n");
free(ptr);
ptr = NULL;
return 0;
}
Malloc
#include <stdio.h>
#include <stdlib.h>
int main() {
int *ptr;
ptr = (int*) malloc(sizeof(int));
if (ptr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("Memory successfully allocated using malloc.\n");
printf("enter a value.\n");
scanf("%d",ptr);
printf("value = %d ", *ptr);
printf("\n");
return 0;
}
Malloc and free
#include <stdio.h>
#include <stdlib.h>
int main() {
int *ptr;
ptr = (int*) malloc(sizeof(int));
if (ptr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("Memory successfully allocated using malloc.\n");
printf("enter a value.\n");
scanf("%d",ptr);
printf("value = %d ", *ptr);
printf("\n");
free(ptr);
printf("after free ptr new value = %d ", *ptr);
return 0;
}
Dynamic memory allocation
1. Malloc - CLICK HERE
2.Free - CLICK HERE
3.Calloc - 1. CLICK HERE 2. CLICK HERE
4.Calloc AND Free - CLICK HERE
5.Realloc - CLICK HERE
Tuesday, March 25, 2025
Operating system examination set 1
1.
To access the services of operating system, the interface is provided by the ___________
a) System calls
b) API
c) Library
d) Assembly instructions
2.
What is the main function of the command interpreter?
a) to get and execute the next user-specified command
b) to provide the interface between the API and application program
c) to handle the files in operating system
d) none of the mentioned
3.
If a process fails, most operating system write the error information to a ______
a) log file
b) another running process
c) new file
d) none of the mentioned
4.
The systems which allow only one process execution at a time, are called __________
a) uniprogramming systems
b) uniprocessing systems
c) unitasking systems
d) none of the mentioned
5.
In operating system, each process has its own __________
a) address space and global variables
b) open files
c) pending alarms, signals and signal handlers
d) all of the mentioned
6.
In Unix, Which system call creates the new process?
a) fork
b) create
c) new
d) none of the mentioned
7.
A set of processes is deadlock if __________
a) each process is blocked and will remain so forever
b) each process is terminated
c) all processes are trying to kill each other
d) none of the mentioned
8. The number of processes completed per unit time is known as __________
a) Output
b) Throughput
c) Efficiency
d) Capacity
9.
What is the degree of multiprogramming?
a) the number of processes executed per unit time
b) the number of processes in the ready queue
c) the number of processes in the I/O queue
d) the number of processes in memory
10.Which of the following do not belong to queues for processes?
a) Job Queueb) PCB queue
c) Device Queue
d) Ready Queue
11. When the process issues an I/O request __________
a) It is placed in an I/O queueb) It is placed in a waiting queue
c) It is placed in the ready queue
d) It is placed in the Job queue
12. What is a long-term scheduler?
a) It selects processes which have to be brought into the ready queue
b) It selects processes which have to be executed next and allocates CPU
c) It selects processes which heave to remove from memory by swapping
d) None of the mentioned
a) It selects processes which have to be brought into the ready queue
b) It selects processes which have to be executed next and allocates CPU
c) It selects processes which heave to remove from memory by swapping
d) None of the mentioned
13.What is a long-term scheduler?
a) It selects processes which have to be brought into the ready queueb) It selects processes which have to be executed next and allocates CPU
c) It selects processes which heave to remove from memory by swapping
d) None of the mentioned
14
What is a short-term scheduler?
a) It selects which process has to be brought into the ready queue
b) It selects which process has to be executed next and allocates CPU
c) It selects which process to remove from memory by swapping
d) None of the mentioned
b) It selects which process has to be executed next and allocates CPU
c) It selects which process to remove from memory by swapping
d) None of the mentioned
15.The primary distinction between the short term scheduler and the long term scheduler is
a) The length of their queuesb) The type of processes they schedule
c) The frequency of their execution
d) None of the mentioned
16. In a time-sharing operating system, when the time slot given to a process is completed, the process goes from the running state to the __________
a) Blocked stateb) Ready state
c) Suspended state
d) Terminated state
17.The context of a process in the PCB of a process does not contain __________
a) the value of the CPU registersb) the process state
c) memory-management information
d) context switch time
18.Which module gives control of the CPU to the process selected by the short-term scheduler?
a) dispatcherb) interrupt
c) scheduler
d) none of the mentioned
19.The interval from the time of submission of a process to the time of completion is termed as
a) waiting timeb) turnaround time
c) response time
d) throughput
20. In priority scheduling algorithm
a) CPU is allocated to the process with highest priorityb) CPU is allocated to the process with lowest priority
c) Equal priority processes can not be scheduled
d) None of the mentioned
21.Process are classified into different groups in ____________
a) shortest job scheduling algorithmb) round robin scheduling algorithm
c) priority scheduling algorithm
d) multilevel queue scheduling algorithm
22.What are the two steps of a process execution?
a) I/O & OS Burstb) CPU & I/O Burst
c) Memory & I/O Burst
d) OS & Memory Burst
23. What is Dispatch latency?
a) the speed of dispatching a process from running to the ready stateb) the time of dispatching a process from running to ready state and keeping the CPU idle
c) the time to stop one process and start running another one
d) none of the mentioned
24. Round robin scheduling falls under the category of ____________
a) Non-preemptive schedulingb) Preemptive scheduling
c) All of the mentioned
d) None of the mentioned
25 The real difficulty with SJF in short term scheduling is ____________
a) it is too good an algorithmb) knowing the length of the next CPU request
c) it is too complex to understand
d) none of the mentioned
26. An SJF algorithm is simply a priority algorithm where the priority is ____________
a) the predicted next CPU burstb) the inverse of the predicted next CPU burst
c) the current CPU burst
d) anything the user wants
27. What is ‘Aging’?
a) keeping track of cache contentsb) keeping track of what pages are currently residing in memory
c) keeping track of how many times a given page is referenced
d) increasing the priority of jobs to ensure termination in a finite time
28. A solution to the problem of indefinite blockage of low – priority processes is ____________
a) Starvationb) Wait queue
c) Ready queue
d) Aging
29. Which one of the following is the address generated by CPU?
a) physical addressb) absolute address
c) logical address
d) none of the mentioned
30. What is compaction?
a) a technique for overcoming internal fragmentationb) a paging technique
c) a technique for overcoming external fragmentation
d) a technique for overcoming fatal error
31. With relocation and limit registers, each logical address must be _______ the limit register.
a) less thanb) equal to
c) greater than
d) none of the mentioned
32. When memory is divided into several fixed sized partitions, each partition may contain ________
a) exactly one processb) at least one process
c) multiple processes at once
d) none of the mentioned
33. In fixed size partition, the degree of multiprogramming is bounded by ___________
a) the number of partitionsb) the CPU utilization
c) the memory size
d) all of the mentioned
34. The first fit, best fit and worst fit are strategies to select a ______
a) process from a queue to put in memoryb) processor to run the next process
c) free hole from a set of available holes
d) all of the mentioned
35. In internal fragmentation, memory is internal to a partition and ____________
a) is being usedb) is not being used
c) is always used
d) none of the mentioned
36. A solution to the problem of external fragmentation is ____________
a) compactionb) larger memory space
c) smaller memory space
d) none of the mentioned
37. Another solution to the problem of external fragmentation problem is to ____________
a) permit the logical address space of a process to be noncontiguousb) permit smaller processes to be allocated memory at last
c) permit larger processes to be allocated memory at last
d) all of the mentioned
38. If relocation is static and is done at assembly or load time, compaction _________
a) cannot be doneb) must be done
c) must not be done
d) can be done
39. When the memory allocated to a process is slightly larger than the process, then ____________
a) internal fragmentation occursb) external fragmentation occurs
c) both internal and external fragmentation occurs
d) neither internal nor external fragmentation occurs
40. Logical memory is broken into fixed-sized blocks called ________
a) framesb) pages
c) backing store
d) none of the mentioned
41.Logical memory is broken into blocks of the same size called _________
a) framesb) pages
c) backing store
d) none of the mentioned
42. Dispatch latency is defined as
a)the speed of dispatching a process from running to the ready state
b)the time of dispatching a process from running to ready state and keeping the CPU idle
c)the time to stop one process and start running another one
d)none of these
43. Consider the following statements about process state transitions for a system using preemptive scheduling.(GATE 2020)
I. A running process can move to ready state.
II. A ready process can move to running state.
III. A blocked process can move to running state.
IV. A blocked process can move to ready state.
a) I, II and III only
b) II and III only
c) I, II and IV only
d) I, II, III and IV only
44. Consider a process P running on a CPU. Which one or more of the following events will always trigger a context switch by the OS that results in process P moving to a non-running state (e.g., ready, blocked)? (GATE 2024)
a)P makes a blocking system call to read a block of data from the disk
b)P tries to access a page that is in the swap space, triggering a page fault
c)An interrupt is raised by the disk to deliver data requested by some other process
d) A timer interrupt is raised by the hardware
45. Which of the following process state transitions is/are NOT possible?(GATE 2024)
a)Running to Ready
b)Waiting to Running
c)Ready to Waiting
d) Running to Terminated
46. Suppose a system contains n processes and system uses the round-robin algorithm for CPU scheduling then which data structure is best suited ready queue of the process
a)stack
b)queue
c)circular queue
d)tree
47. Where does the swap space reside ?
a)RAM
b)Disk
c)ROM
d)On-chip cache
48. Which of the following facilitates sharing of codes, data and program modules between processes?
Segments
Page table
Pages
Segment table
49. In which of the following Page replacement Algorithm making pages replacement decisions in such a manner that the total number of page faults during operation of a process is the minimum possible?
LRU Page replacement Algorithm
FIFO page replacement Algorithm
Optimal page replacement algorithm
NRU Page replacement algorithm
50. In which of the following Page replacement Policy uses the law of locality of reference as the basis for its replacement decisions?
LRU Page replacement Algorithm
FIFO page replacement Algorithm
Optimal page replacement algorithm
NRU Page replacement algorithm
51. Which of the following page replacement algorithm exhibit the stack property ?
LRU Page replacement Algorithm
FIFO page replacement Algorithm
Optimal page replacement algorithm
NRU Page replacement algorithm
52.Belady’s Anomaly occurs in which of the following page replacement algorithm?
LRU Page replacement Algorithm
FIFO page replacement Algorithm
Optimal page replacement algorithm
NRU Page replacement algorithm
53.In which of the following Algorithm where the reference bit is used to determine whether a page has been recently referenced, and some page that has not been recently referenced is replaced?
LRU Page replacement Algorithm
FIFO page replacement Algorithm
Optimal page replacement algorithm
NRU Page replacement algorithm
54. ______memory allocation avoid problems of wastage of memory and the problems of underestimating the memory size
Dynamic memory allocation
Static memory allocation
contiguous memory allocation
None-Contiguous memory allocation
55. ____ section is dynamically allocated memory to a process during its run time
stack
Text
Data
Heap
56. From the point of view of a particular process, the important criterion is how long it takes to execute that process. The interval from the time of submission of a process to the time of completion is the ____
Throughput
Waiting time
Turnaround time
Response time
57. It is desirable to ______.
minimize CPU utilization and throughput and to maximize turnaround time, waiting time, and response time
maximize CPU utilization and throughput and to minimize turnaround time, waiting time, and response time
maximize CPU utilization and turnaround time and to minimize throughput, waiting time, and response time
minimize waiting time and throughput and to maximize turnaround time, CPU utilization, and response time
58. Which of the following scheduling algorithm is nonpreemptive
Shortest-Job-First Scheduling
First-Come, First-Served Scheduling
Priority Scheduling
Round-Robin Scheduling
59. Which of the following scheduling algorithm associates with each process the length of the process’s next CPU burst
Shortest-Job-First Scheduling
First-Come, First-Served Scheduling
Priority Scheduling
Round-Robin Scheduling
60. ____ is sometimes called shortest-remaining-time-first scheduling
Round-Robin Scheduling
Preemptive SJF scheduling
Priority Scheduling
First-Come, First-Served Scheduling
| Process | Arrival time | Burst time |
| P0 | 0 | 8 |
| P1 | 1 | 6 |
| p2 | 2 | 4 |
| p3 | 3 | 2 |
| p4 | 4 | 1 |
61. Calculate average waiting time using SRTF.
62. Calculate average turn around time using SRTF.
63. Calculate average response using SRTF.
64. Calculate average waiting time using RR with quantum size=2.
62. Calculate average turn around time using RR with quantum size=2..
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