diff --git a/count-vowel-substrings-of-a-string/sol.go b/count-vowel-substrings-of-a-string/sol.go
new file mode 100644
index 0000000..b121447
--- /dev/null
+++ b/count-vowel-substrings-of-a-string/sol.go
@@ -0,0 +1,42 @@
+package main
+
+func vowel(char rune) (int, bool) {
+	v, ok := map[rune]int{
+		'a': 0b00001,
+		'e': 0b00010,
+		'i': 0b00100,
+		'o': 0b01000,
+		'u': 0b10000,
+	}[char]
+	return v, ok
+}
+
+func countVowelSubstrings(word string) int {
+	order := make([]int, 0)
+	counts := make(map[int]int)
+	last, m, count := 0, 1, 0
+	for _, char := range word {
+		if last == 0b11111 {
+			count += m
+		}
+		vow, ok := vowel(char)
+		if !ok {
+			order = make([]int, 0)
+			counts = make(map[int]int)
+			last, m = 0, 1
+		} else {
+			for len(order) > 0 && (order[0] == vow || counts[order[0]] > 1) {
+				counts[order[0]]--
+				order = order[1:]
+				m++
+			}
+			last |= vow
+			order = append(order, vow)
+			counts[vow]++
+		}
+	}
+	if last == 0b11111 {
+		count += m
+	}
+	return count
+}