Merge pull request #1 from Benezivas/oldproblems

Include problems from the algobattle directory, s.t. they can be removed from that repository.

Author: Benezivas

.github/workflows/python-app.yml

@@ -0,0 +1,40 @@
+# This workflow will install Python dependencies, run tests and lint with a single version of Python
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: Algorithmic Battle - Problem Files
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.9
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install flake8 flake8-docstrings
+        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        git clone https://github.com/Benezivas/algobattle.git
+        cd algobattle && pip install . --user && cd ..
+    - name: Lint with flake8
+      run: |
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --exit-zero --select=E9,F63,F7,F82 --show-source --statistics --exclude algobattle
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics \
+        --per-file-ignores="__init__.py:F401,D104 */solver/main.py:D100 */generator/main.py:D100" \
+        --docstring-convention numpy --ignore=D100,D105,D102,W503 --exclude algobattle
+    - name: Test with unittest
+      run: |
+        python -m unittest

README.md

@@ -7,4 +7,4 @@ Clone the [algobattle](https://github.com/Benezivas/algobattle) repository:
 git clone https://github.com/Benezivas/algobattle.git
 ```
 Follow the installation and usage instructions in the `README`.
-Use the problem folders as input paths for the `battle` script.
+Use the specific problem folders as input paths for the `battle` script.

problems/README.md

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+# Problem Files used in Practice
+This directory contains several problem tasks that you may use for your
+students. Each problem directory contains a `README.md` describing the problem
+and the I/O that the generator and solver use. The `generator` and `solver`
+directories contain dummy solvers that output instances which are technically
+legal, but rather unexiting.
+
+The simplest problem is currently the `pairsum` problem, which well suited as a
+primer task at the start of the lab. For this task, a simple randomized
+generator and solver are implemented which you may use for to see how the
+program behaves when the solver runs into a timeout at some instance size.

problems/biclique/README.md

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+# The Bipartite Clique Problem
+The *Bipartite Clique* problem is closely related to the *Maximum Clique*
+problem. In it, we want to find the biggest complete bipartite subgraph in a
+given Graph.
+
+**Given**: Undirected graph `G = (V,E)` with `|V(G)| = n`  
+**Problem**: Find the biggest subgraph `G' = (V_1 union V_2, E')` of `G` such that
+`G' = K_{i,j}`
+
+The generator is given an instance size and outputs an undirected graph of at most this size.
+Along with the graph, it outputs a certificate solution for the biggest
+bipartite clique of the graph that it knows.
+
+The solver then receives this graph and has to find a bipartite clique of
+maximum size within the time limit and output it. The solution is valid if its
+size is at least as big as the certificate solution of the generator.
+
+# I/O
+We use a format similar to the DIMACS-format for this task:
+* **Edges**: These lines are of the form `e i j`
+    for an edge `(i,j) in E(G)`. As we are working on an undirected graph, 
+    the symmetrical edge `(j,i)` does not need to be supplied.
+* **Solution lines**: For each node `i` of `V_1(G')` add a line `s set1 i`,
+    accordingly a line `s set2 j` for each node `j` of `V_2(G')`.
+
+Isolated nodes can not be part of a bipartite clique, thus this format does not
+allow supplying them in an instance.
+
+Any malformed lines or lines not following the format above are discarded.
+Each of the lines described above are to be written into their own line.
+The generator reads the instance size from `stdin` and writes its instance 
+and certificate to `stdout`. The order of the lines does not matter. For an
+instance size of `n`, vertices may only be given indices in `{1,...,n}`.
+
+The following output is a valid stream to stdout for the generator, given 
+`n >= 10` (line breaks inserted for better readability):
+```
+    The described graph contains a K_{2,3} between {7,9} and {6,8,10}\n
+    s set1 7\n
+    s set1 9\n
+    s set2 6\n
+    s set2 8\n
+    s set2 10\n
+    e 1 2\n
+    e 2 3\n
+    e 2 8\n
+    e 8 5\n
+    e 8 10\n
+    e 8 7\n
+    e 6 5\n
+    e 6 7\n
+    e 6 9\n
+    e 10 9\n
+    e 10 7
+```
+The solver receives all edge lines, seperated by line breaks, just like above,
+via `stdin`. It is then supposed to output edge sets `E'` and `E''` as described
+above to `stdout`. The solution may deviate from that of the generator.
+
+For the instance above, a valid output of the solver may look like this:
+```
+    s set1 8\n
+    s set1 6\n
+    s set1 10\n
+    s set2 9\n
+    s set2 7
+```

problems/biclique/__init__.py

@@ -0,0 +1 @@
+from .problem import Biclique as Problem

problems/biclique/__pycache__/__init__.cpython-39.pyc

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+FROM python:3
+
+COPY main.sh /
+COPY main.py /
+
+CMD ["./main.sh"]