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2 ZigZag LeetCode in Python and Deployment with Flask, Docker, and Kubernetes
In this tutorial, we will first solve the LeetCode problem “2 ZigZag” in Python. Then, we will deploy our solution using Flask, Docker, and Kubernetes.
Step 1: Solve the LeetCode problem “2 ZigZag” in Python
The LeetCode problem “2 ZigZag” asks us to convert a given string into a zigzag pattern given a number of rows. We can solve this problem by iterating over the string and assigning each character to the correct row in the zigzag pattern.
“`python
def convert(s, numRows):
if numRows == 1 or numRows >= len(s):
return s
zigzag = [” for _ in range(numRows)]
row = 0
direction = 1
for char in s:
zigzag[row] += char
if row == 0:
direction = 1
elif row == numRows – 1:
direction = -1
row += direction
return ”.join(zigzag)
“`
Now that we have our solution to the “2 ZigZag” problem, let’s move on to deploying it using Flask, Docker, and Kubernetes.
Step 2: Deployment with Flask
First, we need to create a Flask web application that will expose our “2 ZigZag” solution as an API endpoint.
“`python
from flask import Flask, request, jsonify
app = Flask(__name__)
@app.route(‘/zigzag’, methods=[‘POST’])
def zigzag():
data = request.get_json()
s = data[‘s’]
numRows = data[‘numRows’]
result = convert(s, numRows)
return jsonify({‘result’: result})
if __name__ == ‘__main__’:
app.run()
“`
Save the above code to a file named `app.py`.
Step 3: Deployment with Docker
Next, we will create a Dockerfile to build our Flask application into a Docker image.
“`Dockerfile
FROM python:3.9
COPY . /app
WORKDIR /app
RUN pip install Flask
EXPOSE 5000
CMD [“python”, “app.py”]
“`
Save the above code to a file named `Dockerfile`.
Now, we can build our Docker image by running the following command:
“`shell
docker build -t zigzag-flask .
“`
Finally, we can run our Docker container with the following command:
“`shell
docker run -p 5000:5000 zigzag-flask
“`
Step 4: Deployment with Kubernetes
Now, we will deploy our Flask application using Kubernetes.
First, we need to create a Kubernetes Deployment manifest file:
“`yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: zigzag-flask
spec:
replicas: 1
selector:
matchLabels:
app: zigzag-flask
template:
metadata:
labels:
app: zigzag-flask
spec:
containers:
– name: zigzag-flask
image: zigzag-flask
ports:
– containerPort: 5000
“`
Save the above code to a file named `deployment.yaml`.
Next, we can deploy our Flask application to Kubernetes with the following command:
“`shell
kubectl apply -f deployment.yaml
“`
Now, our Flask application is running in a Kubernetes cluster and can be accessed at the exposed NodePort.
Conclusion
In this tutorial, we solved the “2 ZigZag” problem in Python and deployed our solution using Flask, Docker, and Kubernetes. We created a Flask application that exposes our solution as an API endpoint, built a Docker image for our Flask application, and deployed it to a Kubernetes cluster. We hope you found this tutorial helpful!
