Question

Write a program to have Karel build a pyramid. There should be three balls on the first row, two in the second row, and one in the third row.

World: PyramidOfKarel
Starting World

Ending World

Answer 1

Certainly! Below is a Python program to control Karel the Robot and build a pyramid as described, where Karel will place three balls on the first row, two in the second row, and one in the third row. This program assumes you are using a Karel simulation environment that accepts Python syntax.

### Karel Pyramid Building Program

```python
def turn_right():
for _ in range(3):
turn_left()

def build_pyramid():
# Building the first row (3 balls)
for _ in range(3):
put_ball()
if _ < 2: # Move right only if not at the last ball of the row
move()
# Move to the next row position
turn_left()
move()
turn_left()

# Building the second row (2 balls)
for _ in range(2):
put_ball()
if _ < 1: # Move right only if not at the last ball of the row
move()
# Move to the next row position
turn_left()
move()
turn_left()

# Building the third row (1 ball)
put_ball()

# Starting Karel's actions
def main():
# Ensure Karel is facing north at the start
while not facing_north():
turn_left()

build_pyramid()

# Execute the main function
if __name__ == "__main__":
main()
```

### Explanation of the Code:

1. **turn_right()** - A function to turn Karel right (three left turns).

2. **build_pyramid()** - This function is where Karel builds the pyramid:
- It starts by building the first row with three balls.
- Karel then moves to the next row downwards and builds two balls.
- Finally, Karel moves down again and places a single ball for the top of the pyramid.

3. **main()** - This function ensures Karel is facing the correct direction (north) before starting the pyramid building process.

### Instructions for Running the Program:

1. Open your Karel simulation environment and select the world named "PyramidOfKarel".
2. Run the provided Python code in that environment.
3. Observe Karel build the pyramid according to the specified pattern.

This program structure assumes you have implemented `move()`, `put_ball()`, `turn_left()`, and `facing_north()` functions in your Karel environment. Adjust as needed based on your specific programming environment and language syntax.