Update 301-remove-invalid-parentheses.js

Author: everthis

301-remove-invalid-parentheses.js

@@ -1,3 +1,37 @@
+/**
+ * @param {string} s
+ * @return {string[]}
+ */
+const removeInvalidParentheses = function(s) {
+  const res = []
+  helper(s, 0, 0, ['(', ')'])
+  return res
+
+  function helper(str, lastI, lastJ, pair) {
+    let openNum = 0, closeNum = 0
+    for(let i = lastI; i < str.length; i++) {
+      if(str[i] === pair[0]) openNum++
+      if(str[i] === pair[1]) closeNum++
+      if(closeNum > openNum) {
+        for(let j = lastJ; j <= i; j++) {
+          if(str[j] === pair[1] && (j === lastJ || str[j - 1] !== pair[1])) {
+            helper(str.slice(0, j) + str.slice(j + 1), i, j, pair)
+          }
+        }
+        return
+      }
+    }
+    let rev = str.split('').reverse().join('')
+    if(pair[0] === '(') {
+      helper(rev, 0, 0, [')', '('])
+    } else {
+      res.push(rev)
+    }
+  }
+};
+
+// another
+
 /**
  * @param {string} s
  * @return {string[]}