Merge pull request neetcode-gh#372 from 7thPorter/7-reverse-integer

feat: JavaScript solution to No. 7 Reverse Integer

Author: neetcode-gh

javascript/7-Reverse-Integer.js

@@ -0,0 +1,27 @@
+/**
+ * @param {number} x
+ * @return {number}
+ */
+const reverse = function (x) {
+  const max = 2 ** 31 - 1;
+  const min = -(2 ** 31);
+
+  let result = 0;
+  while (x !== 0) {
+    const digit = x % 10;
+    x = Math.trunc(x / 10);
+
+    if (result > max / 10 || (result === max / 10 && digit >= max % 10)) {
+      return 0;
+    } else if (
+      result < min / 10 ||
+      (result === max / 10 && digit <= min % 10)
+    ) {
+      return 0;
+    } else {
+      result = result * 10 + digit;
+    }
+  }
+
+  return result;
+};