diff --git a/20_valid_parentheses/main.cpp b/20_valid_parentheses/main.cpp
new file mode 100644
index 0000000..0d73ef4
--- /dev/null
+++ b/20_valid_parentheses/main.cpp
@@ -0,0 +1,43 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+public:
+    bool isValid(string s) {
+        stack<char> stk;
+
+        for (auto c : s) {
+            switch (c) {
+                case '(':
+                case '[':
+                case '{':
+                    stk.emplace(c);
+                    break;
+                case ')':
+                    if (stk.empty() || '(' != stk.top()) {
+                        return false;
+                    }
+                    stk.pop();
+                    break;
+                case ']':
+                    if (stk.empty() || '[' != stk.top()) {
+                        return false;
+                    }
+                    stk.pop();
+                    break;
+                case '}':
+                    if (stk.empty() || '{' != stk.top()) {
+                        return false;
+                    }
+                    stk.pop();
+                    break;
+            }
+        }
+
+        if (!stk.empty()) {
+            return false;
+        }
+
+        return true;
+    }
+};