Fix subtree size accessing

file.hpp

@@ -4,7 +4,6 @@
 
 using std::string;
 typedef unsigned long long count_type;
-#define RAND_MAX (1 << 62)
 class line;
 typedef std::pair<line*, line*> two_lines;
 
@@ -35,13 +34,13 @@ class file {
 		if(get_size(l->left) > k) {
 			// In the left subtree
 			auto two = split(l->left, k);
-			l->size -= two.first->size;
+			l->size -= get_size(two.first);
 			return {two.first, l};
 		}
 		else {
 			// In the right subtree
 			auto two = split(l->right, k - (1+get_size(l->left)));
-			l->size -= two.second->size;
+			l->size -= get_size(two.second);
 			return {l, two.second};
 		}
 	}
@@ -80,6 +79,7 @@ public:
 		srand(120);
 		root = nullptr;
 	}
+	// File access
 	// Don't find index k, but k-th line -> +1
 	line* find(count_type k) {
 		if(k >= root->size)
@@ -87,7 +87,7 @@ public:
 		return find(root, k+1);
 	}
 
-	// File access
+	// Line insert
 	void insert(int k, string s) {
 		line *l = new line(rand(), s);