feat: solve reverse bits

Author: GangBean

reverse-bits/GangBean.java

@@ -0,0 +1,24 @@
+public class Solution {
+    // you need treat n as an unsigned value
+    public int reverseBits(int n) {
+        /**
+        1. understanding
+        - return the reversed 32 bit input num
+        2. strategy
+        - assign stack
+        - iterate until stack.size is 32
+        - push value % 2, and value /= 2
+        3. complexity
+        - time: O(1)
+        - space: O(1)
+        */
+        int reversed = 0;
+        for (int i = 0; i < 32; i++) {
+            reversed <<= 1;
+            reversed |= n & 1;
+            n >>= 1;
+        }
+        return reversed;
+    }
+}
+