1 files changed, 26 insertions, 0 deletions
diff --git a/content/datastructures/unionFind.cpp b/content/datastructures/unionFind.cpp
new file mode 100644
index 0000000..dd5a569
--- /dev/null
+++ b/content/datastructures/unionFind.cpp
@@ -0,0 +1,26 @@
+// unions[i] >= 0 => unions[i] =  parent
+// unions[i]  < 0 => unions[i] = -size
+vector<int> unions;
+
+void init(int n) { //Initialisieren
+	unions.assign(n, -1);
+}
+
+int findSet(int a) { // Pfadkompression
+	if (unions[a] < 0) return a;
+	return unions[a] = findSet(unions[a]);
+}
+
+void linkSets(int a, int b) { // Union by size.
+	if (unions[b] > unions[a]) swap(a, b);
+	unions[b] += unions[a];
+	unions[a] = b;
+}
+
+void unionSets(int a, int b) { // Diese Funktion aufrufen.
+	if (findSet(a) != findSet(b)) linkSets(findSet(a), findSet(b));
+}
+
+int size(int a) {
+	return -unions[findSet(a)];
+}