Short Encoding of Words

Problem Description

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.

Solution (Go)

func minimumLengthEncoding(words []string) int {
	wordsMap := make(map[string]bool)
	for _, w := range words {
		wordsMap[w] = true
	}
	for _, w := range words {
		for i := 0; i < len(w); i++ {
			subStr := w[i+1:]
			if _, ok := wordsMap[subStr]; ok {
				delete(wordsMap, subStr)
			}
		}
	}
	res := 0
	for w := range wordsMap {
		res += len(w) + 1
	}
	return res
}