07 initial

Author: mzeeshan138

07-Reverse-Integer.js

@@ -0,0 +1,30 @@
+/**
+ * @param {number} x
+ * @return {number}
+ */
+var reverse = function (x) {
+  let rev = 0;
+  const INT_MAX = 2147483647; // 2^31 - 1
+  const INT_MIN = -2147483648; // -2^31
+
+  while (x !== 0) {
+    let pop = x % 10; // extract last digit
+    x = Math.trunc(x / 10); // remove last digit
+
+    // Check overflow before multiplying
+    if (
+      rev > Math.trunc(INT_MAX / 10) ||
+      (rev === Math.trunc(INT_MAX / 10) && pop > 7)
+    )
+      return 0;
+    if (
+      rev < Math.trunc(INT_MIN / 10) ||
+      (rev === Math.trunc(INT_MIN / 10) && pop < -8)
+    )
+      return 0;
+
+    rev = rev * 10 + pop;
+  }
+
+  return rev;
+};