valid-parentheses solutions

Author: Blossssom

valid-parentheses/Blossssom.ts

@@ -0,0 +1,47 @@
+/**
+ * @param s - 괄호 문자열
+ * @returns - 올바르게 열고 닫혔는지 반환
+ */
+// function isValid(s: string): boolean {
+//   const parentheses: Record<string, boolean> = {
+//     "()": true,
+//     "{}": true,
+//     "[]": true,
+//   };
+//   const stack: string[] = [];
+//   for (const st of s) {
+//     if (
+//       !stack.length ||
+//       parentheses[`${stack[stack.length - 1]}${st}`] === undefined
+//     ) {
+//       stack.push(st);
+//     } else {
+//       stack.pop();
+//     }
+//   }
+//   return stack.length ? false : true;
+// }
+
+function isValid(s: string): boolean {
+  const parentheses: Record<string, string> = {
+    "(": ")",
+    "{": "}",
+    "[": "]",
+  };
+
+  const stack: string[] = [];
+  for (const char of s) {
+    if (parentheses[char]) {
+      stack.push(char);
+    } else {
+      const last = stack.pop();
+      if (last === undefined || parentheses[last] !== char) {
+        return false;
+      }
+    }
+  }
+
+  return !stack.length;
+}
+
+