Questions in: Application Developer

Right Answer:
The probability that the stone lies near the center of the circle depends on how you define "near." If you specify a smaller circle with radius ( r_1 < r ) around the center, the probability is the area of the smaller circle divided by the area of the larger circle:

[ P = frac{pi r_1^2}{pi r^2} = frac{r_1^2}{r^2} ]

Without a specific definition of "near," the probability cannot be determined.

Right Answer:
When you create a pointer for the abstract class and point it to the derived class object, calling the function `x()` will invoke the implementation in the derived class, assuming it overrides the abstract method.

Right Answer:
Windows OS is a proprietary operating system developed by Microsoft, while Ubuntu is a free and open-source operating system based on Linux. Windows typically has a more user-friendly interface and is widely used for commercial software, whereas Ubuntu is known for its security, customization, and is often preferred for development and server environments.

Right Answer:
Heap sort is a comparison-based sorting algorithm that uses a binary heap data structure to sort elements, achieving a time complexity of O(n log n). Insertion sort, on the other hand, builds the sorted array one element at a time by repeatedly taking an element from the unsorted portion and inserting it into the correct position in the sorted portion, with a time complexity of O(n^2) in the worst case.

Right Answer:
```python
def towers_of_hanoi(n, source, target, auxiliary):
if n == 1:
print(f"Move disk 1 from {source} to {target}")
return
towers_of_hanoi(n - 1, source, auxiliary, target)
print(f"Move disk {n} from {source} to {target}")
towers_of_hanoi(n - 1, auxiliary, target, source)

# Example usage:
towers_of_hanoi(3, 'A', 'C', 'B')
```

Right Answer:
A semaphore is a signaling mechanism that can allow multiple threads to access a resource, while a mutex (mutual exclusion) is a locking mechanism that allows only one thread to access a resource at a time.

Right Answer:
The minimum number of races required is 7.

Right Answer:
To exchange the positions of A and B using the engine, follow these steps:

1. Move the engine forward to the end of bogie A.
2. Turn the engine to the left (obtuse angle) and push bogie A forward.
3. Move the engine back to its original position.
4. Now, turn the engine to the right (obtuse angle) and push bogie B forward.
5. Finally, move the engine back to the original position to complete the exchange.

Right Answer:
Arrange the 10 coins in the shape of a star, where each point of the star and the intersection point contains a coin. This way, you will have 4 rows, each containing 4 coins.

Right Answer:
```python
def substring_after_char_count(s, char, count):
occurrences = 0
index = -1

for i in range(len(s)):
if s[i] == char:
occurrences += 1
if occurrences == count:
index = i
break

if occurrences < count or index == -1:
return ""

return s[index + 1:]

# Example usage
string = "This is demo string"
character = 'i'
count = 3
output = substring_after_char_count(string, character, count)
print(output) # Output: "ng"
```

Right Answer:
**Basic GUI Design:**

1. **Home Page:**
- Search bar for movies
- List of currently showing movies with posters
- Links to user login and registration

2. **Movie Details Page:**
- Movie title, description, showtimes, and ratings
- "Book Now" button

3. **Booking Page:**
- Select theatre and showtime
- Seat selection (interactive seating chart)
- User login/registration prompt if not logged in
- Payment details form (including saved card option)

4. **User Profile Page:**
- View past bookings
- Rate movies
- Manage saved card details

**Database Tables:**

1. **Users Table:**
- user_id (PK)
- username
- password_hash
- email
- saved_card_details

2. **Movies Table:**
- movie_id (PK)
- title
- description

Right Answer:
```python
def print_paths(start, end, path=[]):
path.append(start)

if start == end:
print(" -> ".join(map(str, path)))
elif start < end:
print_paths(start + 1, end, path)
print_paths(start + 2, end, path)

path.pop()

# Example usage
start_position = 0
end_position = 4
print_paths(start_position, end_position)
```

Right Answer:
To generate a tree with a maximum height of 3 from the given CSV values, follow these steps:

1. Read the CSV file and parse the values into a list.
2. Create a root node labeled "E".
3. For each entry (e.g., E1:12), create child nodes under "E" for E1, E2, ..., En based on the values present in the file.
4. For each child node (e.g., E1), check for its children (E11, E12, ..., E1n) and add them as children of E1 only if E1 exists in the file.
5. Repeat this for the second level, ensuring that nodes are only added if their parent exists in the file.
6. Stop adding nodes once the height of the tree reaches 3.

This will ensure that the tree is constructed correctly according to the given restrictions.

Right Answer:
```c
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

void reverseWords(char *str) {
int n = strlen(str);
char *result = (char *)malloc(n + 1);
int j = 0;

for (int i = n - 1; i >= 0; i--) {
if (str[i] == ' ') {
result[j++] = ' ';
} else {
int start = i;
while (i >= 0 && str[i] != ' ') i--;
for (int k = i + 1; k <= start; k++) {
result[j++] = str[k];
}
}
}
result[j] = '';
printf("%sn", result);
free(result);
}

int main() {
char str[] = "Oracle @ App Dev";
reverseWords(str);
return 0;
}
```

Right Answer:
The game is not fair; Player Y has a higher probability of winning.

Right Answer:
Load 40 bags of 15 kg and 36 bags of 25 kg.

Right Answer:
```python
def insert_numbers(file_path, n1, n2):
with open(file_path, 'a') as file:
# Read existing numbers to check for overlaps
existing_ranges = []
try:
with open(file_path, 'r') as read_file:
for line in read_file:
existing_ranges.append(tuple(map(int, line.strip().split(','))))
except FileNotFoundError:
pass

# Check if the new range overlaps with existing ranges
for (start, end) in existing_ranges:
if not (n2 < start or n1 > end):
print("Overlap detected. Cannot insert.")
return

# If no overlap, write the new range
file.write(f"{n1},{n2}n")

# Example usage
insert_numbers('numbers.txt', 4, 6)
insert_numbers('numbers.txt', 7, 9) # This will work
insert_numbers('numbers

Right Answer:
2 times.

Right Answer:
Multitasking refers to the ability of an operating system to execute multiple tasks or processes simultaneously by rapidly switching between them, giving the illusion that they are running at the same time. Multiprogramming, on the other hand, is a method where multiple programs are loaded into memory and the CPU switches between them to maximize resource utilization, allowing for better performance and efficiency.

Right Answer:
The last ball that will be left is a red ball.