Create 1704-determine-if-string-halves-are-alike.js

Author: everthis

1704-determine-if-string-halves-are-alike.js

@@ -0,0 +1,19 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+const halvesAreAlike = function(s) {
+  const set = new Set(['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'])
+  const n = s.length
+  const mid = n / 2
+  const first = s.slice(0, mid), second = s.slice(mid)
+  return chk(first, set) === chk(second, set)
+};
+
+function chk(str, set) {
+  let res = 0
+  for(let i = 0, len = str.length; i < len; i++) {
+    if(set.has(str[i])) res++
+  }
+  return res
+}