Solve problem '190) reverse bits'

Author: ozantopal

problems/190-reverse-bits/README.md

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+Reverse bits of a given 32 bits unsigned integer.
+
+**Note:**
+
+- Note that in some languages, such as Java, there is no unsigned integer type. In this case, both input and output will be given as a signed integer type. They should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned.
+- In Java, the compiler represents the signed integers using [2's complement notation](https://en.wikipedia.org/wiki/Two%27s_complement). Therefore, in **Example 2** above, the input represents the signed integer `-3` and the output represents the signed integer `-1073741825`.
+
+**Example 1:**
+
+```
+Input: n = 00000010100101000001111010011100
+Output:    964176192 (00111001011110000010100101000000)
+Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000.
+```
+
+**Example 2:**
+
+```
+Input: n = 11111111111111111111111111111101
+Output:   3221225471 (10111111111111111111111111111111)
+Explanation: The input binary string 11111111111111111111111111111101 represents the unsigned integer 4294967293, so return 3221225471 which its binary representation is 10111111111111111111111111111111.
+```
+
+**Constraints:**
+
+- The input must be a **binary string** of length `32`
+
+**Follow up:** If this function is called many times, how would you optimize it?

problems/190-reverse-bits/main.go

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+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(reverseBits(43261596))
+	fmt.Println(reverseBits(4294967293))
+}
+
+func reverseBits(num uint32) uint32 {
+	var result uint32
+	for i := 0; i < 32; i++ {
+		result = result<<1 | num&1
+		num >>= 1
+	}
+	return result
+}