merge mzuenni changes

1 files changed, 27 insertions, 0 deletions

diff --git a/datastructures/pbds.cpp b/datastructures/pbds.cpp
new file mode 100644
index 0000000..a0e5383
--- /dev/null
+++ b/datastructures/pbds.cpp
@@ -0,0 +1,27 @@
+#include <ext/pb_ds/priority_queue.hpp>
+template<typename T>
+using pQueue = __gnu_pbds::priority_queue<T>; //<T, greater<T>>
+auto it = pq.push(5); // O(1)
+pq.modify(it, 6);     // O(log n)
+pq.erase(it);         // O(log n)
+pq.join(pq2);         // O(1)
+pq.swap(pq2);         // O(1)
+
+#include <ext/pb_ds/assoc_container.hpp>
+using namespace __gnu_pbds;
+template<typename T>
+using Tree = tree<T, null_type, less<T>, rb_tree_tag,
+                  tree_order_statistics_node_update>;
+T.order_of_key(x); // number of elements strictly less than x
+auto it = T.find_by_order(k); // k-th element
+
+template<typename T>
+struct chash {
+	const uint64_t C = ll(2e18 * acos(-1)) | 199; // random odd
+	size_t operator()(T o) const {
+		return __builtin_bswap64(hash<T>()(o) * C);
+}};
+template<typename K, typename V>
+using hashMap = gp_hash_table<K, V, chash<K>>;
+template<typename T>
+using hashSet = gp_hash_table<T, null_type, chash<T>>;