Valid Parentheses 풀이

bangdori/Valid Parentheses.js

@@ -0,0 +1,45 @@
+const bracketMap = {
+  "]": -1,
+  ")": -2,
+  "}": -3,
+  "[": 1,
+  "(": 2,
+  "{": 3,
+};
+
+var isValid = function (s) {
+  if (bracketMap[s[0]] < 0) {
+    return false;
+  }
+
+  const stack = [];
+
+  for (let i = 0; i < s.length; i += 1) {
+    const symbol = bracketMap[s[i]];
+
+    if (isOpenBracket(symbol)) {
+      stack.push(symbol);
+      continue;
+    }
+
+    if (isEmptyStack(stack)) {
+      return false;
+    }
+
+    if (stack[stack.length - 1] === symbol * -1) {
+      stack.pop();
+    } else {
+      stack.push(symbol);
+    }
+  }
+
+  return isEmptyStack(stack);
+};
+
+function isEmptyStack(stack) {
+  return stack.length === 0;
+}
+
+function isOpenBracket(symbol) {
+  return symbol > 0;
+}