Init

1 files changed, 15 insertions, 0 deletions

diff --git a/progs/a170.py b/progs/a170.py
new file mode 100644
index 0000000..2c39536
--- /dev/null
+++ b/progs/a170.py
@@ -0,0 +1,15 @@
+from collections import deque

+def check_expression(exp):

+    if len(exp) & 1:

+        return False

+    stack = deque()

+    for ch in exp:

+        if ch == '(' or ch == '{' or ch == '[':

+            stack.append(ch)

+        if ch == ')' or ch == '}' or ch == ']':

+            if not stack:

+                return False

+            top = stack.pop()

+            if (top == '(' and ch != ')') or (top == '{' and ch != '}' or (top == '[' and ch != ']')):

+                return False

+    return not stack
\ No newline at end of file