fix: add security

src/ex09.rs

@@ -68,9 +68,14 @@ fn eval_tree(node: TreeNodeRef, sets: Vec<Vec<i32>>) -> Vec<i32> {
 
 pub fn eval_set(formula: &str, sets: Vec<Vec<i32>>) -> Vec<i32> {
 	let tree: TreeNodeRef = create_tree(conjunctive_normal_form(formula).as_str());
+
 	let mut variables: Vec<char> = get_variables(formula);
+	if variables.len() > sets.len() {
+		panic!("Not enough sets");
+	}
 	variables.sort();
-	let mut result = eval_tree(tree, sets);
+
+	let mut result: Vec<i32> = eval_tree(tree, sets);
 	result.sort();
 
 	return result;

src/tree.rs

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, rc::Rc};
+use std::{cell::RefCell, cmp::Ordering, rc::Rc};
 
 #[derive(Debug, Clone)]
 pub enum NodeValue {
@@ -124,7 +124,12 @@ pub fn create_tree(expression: &str) -> TreeNodeRef {
 		}
 		stack.push(node);
 	}
-	stack.pop().unwrap()
+
+	match stack.len().cmp(&1usize) {
+		Ordering::Greater => panic!("Too many operands, not enough operators."),
+		Ordering::Equal => return stack.pop().unwrap(),
+		Ordering::Less => panic!("Empty formula"),
+	}
 }
 
 pub fn eval_tree(node: TreeNodeRef) -> bool {