06. Short Encoding of Words.cpp

/*
Short Encoding of Words
=======================

A valid encoding of an array of words is any reference string s and array of indices indices such that:

words.length == indices.length
The reference string s ends with the '#' character.
For each index indices[i], the substring of s starting from indices[i] and up to (but not including) the next '#' character is equal to words[i].
Given an array of words, return the length of the shortest reference string s possible of any valid encoding of words.

Example 1:
Input: words = ["time", "me", "bell"]
Output: 10
Explanation: A valid encoding would be s = "time#bell#" and indices = [0, 2, 5].
words[0] = "time", the substring of s starting from indices[0] = 0 to the next '#' is underlined in "time#bell#"
words[1] = "me", the substring of s starting from indices[1] = 2 to the next '#' is underlined in "time#bell#"
words[2] = "bell", the substring of s starting from indices[2] = 5 to the next '#' is underlined in "time#bell#"

Example 2:
Input: words = ["t"]
Output: 2
Explanation: A valid encoding would be s = "t#" and indices = [0].

Constraints:
1 <= words.length <= 2000
1 <= words[i].length <= 7
words[i] consists of only lowercase letters.
*/

class Solution
{
public:
  int minimumLengthEncoding(vector<string> &words)
  {
    unordered_set<string> s(words.begin(), words.end());
    for (auto &w : s)
      for (int i = 1; i < w.size(); ++i)
        s.erase(w.substr(i, w.size() - i));
    int ans = 0;
    for (auto &i : s)
      ans += (i.size() + 1);
    return ans;
  }
};