Unique Morse Code Words

Author: hau

unique_morse_code_words/README.md

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+# Unique Morse Code Words
+
+International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: "a" maps to ".-", "b" maps to "-...", "c" maps to "-.-.", and so on.
+
+For convenience, the full table for the 26 letters of the English alphabet is given below:
+
+```txt
+[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
+```
+
+Now, given a list of words, each word can be written as a concatenation of the Morse code of each letter. For example, "cab" can be written as "-.-..--...", (which is the concatenation "-.-." + ".-" + "-..."). We'll call such a concatenation, the transformation of a word.
+
+Return the number of different transformations among all words we have.
+
+Example:
+
+```txt
+Input: words = ["gin", "zen", "gig", "msg"]
+Output: 2
+Explanation:
+The transformation of each word is:
+"gin" -> "--...-."
+"zen" -> "--...-."
+"gig" -> "--...--."
+"msg" -> "--...--."
+
+There are 2 different transformations, "--...-." and "--...--.".
+```
+
+Note:
+
+- The length of words will be at most 100.
+- Each words[i] will have length in range [1, 12].
+- words[i] will only consist of lowercase letters.

unique_morse_code_words/main.go

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+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("vim-go")
+}
+
+// 26 letters of the English alphabet
+var morseCodes = []string{".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."}
+
+func uniqueMorseRepresentations_1(words []string) int {
+	exist := make(map[string]struct{})
+
+	for _, word := range words {
+		code := ""
+
+		for _, c := range word {
+			code += morseCodes[c-'a']
+		}
+
+		if _, ok := exist[code]; !ok {
+			exist[code] = struct{}{}
+		}
+	}
+
+	return len(exist)
+}

unique_morse_code_words/main_test.go

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+package main
+
+import (
+	"testing"
+
+	"github.com/haunt98/leetcode/pkg/compare"
+)
+
+func TestUniqueMorseRepresentations_1(t *testing.T) {
+	tests := []struct {
+		name  string
+		words []string
+		want  int
+	}{
+		{
+			name:  "example",
+			words: []string{"gin", "zen", "gig", "msg"},
+			want:  2,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := uniqueMorseRepresentations_1(tc.words)
+			compare.Diff(t, tc.want, got)
+		})
+	}
+}