diff --git a/Miscellaneous/util.cpp b/Miscellaneous/util.cpp
new file mode 100644
index 0000000..85c4d2e
--- /dev/null
+++ b/Miscellaneous/util.cpp
@@ -0,0 +1,7 @@
+template <class BidirectionalIterator> // Coordinate compression
+void compress (BidirectionalIterator first, BidirectionalIterator last) {
+	vector<int> tmp(first, last);
+	sort(tmp.begin(), tmp.end());
+	tmp.resize(unique(tmp.begin(), tmp.end()) - tmp.begin());
+	for (auto it = first; it != last; it++) *it = lower_bound(tmp.begin(), tmp.end(), *it) - tmp.begin();
+}