simplify

treap.go

@@ -367,40 +367,25 @@ func (n *node[T]) lcp(item T) (result T, ok bool) {
 	cmp := compare(n.item, item)
 	switch {
 	case cmp > 0:
+		// left rec-descent
 		return n.left.lcp(item)
 	case cmp == 0:
 		// equality is always the shortest containing hull
 		return n.item, true
 	}
 
-	// now on proper depth in tree
-	// first try right subtree for shortest containing hull
-	if n.right != nil {
-		// rec-descent with n.right
-		if compare(n.right.item, item) <= 0 {
-			result, ok = n.right.lcp(item)
-			if ok {
-				return result, ok
-			}
-		} else {
-			// try n.right.left subtree for smallest containing hull
-			// take this path only if n.right.left.item > t.item (this node)
-			if n.right.left != nil && compare(n.right.left.item, n.item) > 0 {
-				// rec-descent with n.right.left
-				result, ok = n.right.left.lcp(item)
-				if ok {
-					return result, ok
-				}
-			}
-		}
+	// right backtracking
+	result, ok = n.right.lcp(item)
+	if ok {
+		return result, ok
 	}
 
 	// not found in right subtree, try this node
 	if covers(n.item, item) {
 		return n.item, true
 	}
 
-	// rec-descent with t.left
+	// left rec-descent
 	return n.left.lcp(item)
 }
 
@@ -455,7 +440,7 @@ func (n *node[T]) scp(item T) (result T, ok bool) {
 		return
 	}
 
-	// rec-descent left subtree
+	// left backtracking
 	if result, ok = n.left.scp(item); ok {
 		return result, ok
 	}
@@ -465,6 +450,7 @@ func (n *node[T]) scp(item T) (result T, ok bool) {
 		return n.item, true
 	}
 
+	// right rec-descent
 	return n.right.scp(item)
 }