public class Solution
extends Object
1864 - Minimum Number of Swaps to Make the Binary String Alternating\.
Medium
Given a binary string `s`, return _the **minimum** number of character swaps to make it **alternating** , or_ `-1` _if it is impossible._
The string is called **alternating** if no two adjacent characters are equal. For example, the strings `"010"` and `"1010"` are alternating, while the string `"0100"` is not.
Any two characters may be swapped, even if they are **not adjacent**.
**Example 1:**
**Input:** s = "111000"
**Output:** 1
**Explanation:** Swap positions 1 and 4: "111000" -> "101010" The string is now alternating.
**Example 2:**
**Input:** s = "010"
**Output:** 0
**Explanation:** The string is already alternating, no swaps are needed.
**Example 3:**
**Input:** s = "1110"
**Output:** -1
**Constraints:**
* `1 <= s.length <= 1000`
* `s[i]` is either `'0'` or `'1'`.