Update algorithm7.rs

Author: hellolutar

exercises/algorithm/algorithm7.rs

@@ -3,7 +3,6 @@
 	This question requires you to use a stack to achieve a bracket match
 */
 
-// I AM NOT DONE
 #[derive(Debug)]
 struct Stack<T> {
 	size: usize,
@@ -31,9 +30,11 @@ impl<T> Stack<T> {
 		self.size += 1;
 	}
 	fn pop(&mut self) -> Option<T> {
-		// TODO
-		None
-	}
+        if self.size > 0 {
+            self.size -= 1;
+        }
+        self.data.pop()
+    }
 	fn peek(&self) -> Option<&T> {
 		if 0 == self.size {
 			return None;
@@ -99,12 +100,41 @@ impl<'a, T> Iterator for IterMut<'a, T> {
 	}
 }
 
-fn bracket_match(bracket: &str) -> bool
-{
-	//TODO
-	true
+fn is_pair(l: char, r: char) -> bool {
+    match (l, r) {
+        ('(', ')') => true,
+        ('[', ']') => true,
+        ('{', '}') => true,
+        _ => false,
+    }
+}
+
+fn bracket_match(bracket: &str) -> bool {
+    let mut bracket_set = std::collections::HashSet::new();
+
+    bracket_set.insert('(');
+    bracket_set.insert(')');
+    bracket_set.insert('[');
+    bracket_set.insert(']');
+    bracket_set.insert('{');
+    bracket_set.insert('}');
+
+    let mut stack = Stack::new();
+    bracket
+        .chars()
+        .filter(|c| bracket_set.contains(c))
+        .for_each(|c| {
+            if stack.peek().is_some_and(|&p| is_pair(p, c)) {
+                stack.pop();
+            } else {
+                stack.push(c);
+            }
+        });
+
+    stack.size == 0
 }
 
+
 #[cfg(test)]
 mod tests {
 	use super::*;
@@ -139,4 +169,4 @@ mod tests {
 		let s = "";
 		assert_eq!(bracket_match(s),true);
 	}
-}
+}