Add ReverseInteger to Baic&NumberTheory

Basic&NumberTheory/Easy/ReverseInteger.java

@@ -0,0 +1,43 @@
+// Name: Mohammad Mubaslat
+// Date: 19/10/2022
+
+// Given a signed 32-bit integer x, return x with its digits reversed. If
+// reversing x causes the value to go outside the signed 32-bit integer range
+// [-231, 231 - 1], then return 0.
+// Assume the environment does not allow you to store 64-bit integers (signed or
+// unsigned).
+
+// Example 1:
+
+// Input: x = 123
+// Output: 321
+// Example 2:
+
+// Input: x = -123
+// Output: -321
+// Example 3:
+
+// Input: x = 120
+// Output: 21
+
+// Constraints:
+
+// -231 <= x <= 231 - 1
+
+class Solution {
+    public int reverse(int x) {
+        int result = 0;
+
+        while (x != 0) {
+            int tail = x % 10;
+            int newResult = result * 10 + tail;
+            if ((newResult - tail) / 10 != result) {
+                return 0;
+            }
+            result = newResult;
+            x = x / 10;
+        }
+
+        return result;
+    }
+}