Added Dijkstra and UnionFind

lucashc · lucashc · commit 201bafb4352a · 2019-09-01T19:55:37.000+02:00
diff --git a/algorithms/dijkstra.py b/algorithms/dijkstra.py
@@ -0,0 +1,19 @@
+# Dijkstra's algorithm
+## \textbf{Note:} Replacing heapq with a priorityqueue from the \ms{queue}-package might be ncessary
+def dijkstra(a, b, nodes):
+    import heapq
+    visited = {}
+    q = [(0, a)]
+    distances = [float('inf') for _ in range(len(nodes))]
+    distances[a] = 0
+    while q:
+        _, current = heapq.heappop(q)
+        if current not in visited:
+            visited.add(current)
+            if current == b: return distances[b]
+            for w, n in nodes[current]:
+                if n in visited: continue
+                if distances[n] > w + distances[current]:
+                    distances[n] = w + distances[current]
+                    heapq.heappush((distances[n], n))
+    return float('inf')
diff --git a/algorithms/union_find.py b/algorithms/union_find.py
@@ -0,0 +1,22 @@
+# Union Find
+class UnionFind:
+    
+    def __init__(self, nodes):
+        self.nodes = list(range(nodes))
+        self.rank = [0]*nodes
+    def union(self, x, y):
+        rootx = self.nodes[x]
+        rooty = self.nodes[y]
+        if self.rank[rootx] > self.rank[rooty]:
+            self.nodes[rooty] = rootx
+        elif self.rank[rootx] < self.rank[rooty]:
+            self.nodes[rootx] = rooty
+        elif rootx != rooty:
+            self.nodes[rooty] = rootx
+            self.rank[rootx] += 1
+    
+    def find(self, x):
+        if self.nodes[x] == x:
+            return x
+        self.nodes[x] = self.find(self.nodes[x])
+        return self.nodes[x]
diff --git a/substitute.py b/substitute.py
@@ -6,6 +6,7 @@
 # Get files in directory
 algorithm_dir = sys.argv[1]
 filelist = [f for f in listdir(algorithm_dir) if isfile(join(algorithm_dir, f))]
+filelist.sort()
 
 def get_lang(f):
     if f[-3:] == ".py": return "python"
@@ -17,6 +18,7 @@ def get_lang(f):
 for f in filelist:
     with open(join(algorithm_dir, f)) as file:
             data = file.read()
+            code = "\n".join([i for i in data.partition('\n')[-1].splitlines() if not i.startswith("##")])
             title = data.splitlines()[0][2:].strip()
             extra_info = "\n\\\\".join([i.strip()[3:] for i in data.splitlines()[1:] if i.startswith("##")])
             inclusion += r"""
@@ -25,7 +27,7 @@ def get_lang(f):
 \begin{lstlisting}[language=%LANGUAGE%]
 %FILE%
 \end{lstlisting}
-""".replace("%LANGUAGE%", get_lang(f)).replace("%FILE%", data.partition('\n')[2]).replace("%TITLE%", title).replace("%EXTRA%", extra_info)
+""".replace("%LANGUAGE%", get_lang(f)).replace("%FILE%", code).replace("%TITLE%", title).replace("%EXTRA%", extra_info)
 
 with open("main.tex") as infile:
     print("Writing to file")
