93 - Restore IP Addresses\.
Medium
A **valid IP address** consists of exactly four integers separated by single dots. Each integer is between `0` and `255` ( **inclusive** ) and cannot have leading zeros.
* For example, `"0.1.2.201"` and `"192.168.1.1"` are **valid** IP addresses, but `"0.011.255.245"`, `"192.168.1.312"` and `"
[email protected]"` are **invalid** IP addresses.
Given a string `s` containing only digits, return _all possible valid IP addresses that can be formed by inserting dots into_ `s`. You are **not** allowed to reorder or remove any digits in `s`. You may return the valid IP addresses in **any** order.
**Example 1:**
**Input:** s = "25525511135"
**Output:** ["255.255.11.135","255.255.111.35"]
**Example 2:**
**Input:** s = "0000"
**Output:** ["0.0.0.0"]
**Example 3:**
**Input:** s = "1111"
**Output:** ["1.1.1.1"]
**Example 4:**
**Input:** s = "010010"
**Output:** ["0.10.0.10","0.100.1.0"]
**Example 5:**
**Input:** s = "101023"
**Output:** ["1.0.10.23","1.0.102.3","10.1.0.23","10.10.2.3","101.0.2.3"]
**Constraints:**
* `0 <= s.length <= 20`
* `s` consists of digits only.