Added more readable solution

go/0202-happy-number.go

@@ -1,35 +1,23 @@
 func isHappy(n int) bool {
-
-	total := 0
-	alreadySeen := make(map[int]bool)
-	for {
+    seen := make(map[int]any)
+	for n != 1 && !contains(seen, n) {
+		seen[n] = struct{}{}
+		n = getNext(n)
+	}
+	return n == 1
+}
 
-		// if we have seen this number
-		if seen := alreadySeen[n]; seen {
-			break
-		}
+func getNext(num int) int {
+	totalSum := 0
+	for num > 0 {
+		digit := num % 10
+		totalSum += digit * digit
+		num /= 10
+	}
+	return totalSum
+}
 
-		alreadySeen[n] = true
-
-		// split n into its individual digits.
-		strn := fmt.Sprint(n)
-
-		// get the length
-		length := len(strn)
-
-		// compute sum of digits
-		for i := 0; i < length; i++ {
-			digit, _ := strconv.Atoi(string(strn[i]))
-			total += (digit * digit)
-		}
-		if total == 1 {
-			return true
-		}
-
-		// reassign n to total
-		n = total
-		total = 0
-   }
-
-return false
-}
+func contains(set map[int]any, val int) bool {
+	_, ok := set[val]
+	return ok
+}

python/0202-happy-number.py

@@ -1,17 +1,14 @@
 class Solution:
     def isHappy(self, n: int) -> bool:
-        slow, fast = n, self.sumSquareDigits(n)
+        seen = set()
+        while n != 1 and n not in seen:
+            seen.add(n)
+            n = self.getNext(n)
+        return n == 1
 
-        while slow != fast:
-            fast = self.sumSquareDigits(fast)
-            fast = self.sumSquareDigits(fast)
-            slow = self.sumSquareDigits(slow)
-
-        return True if fast == 1 else False
-
-    def sumSquareDigits(self, n):
-        output = 0
-        while n:
-            output += (n % 10) ** 2
-            n = n // 10
-        return output
+    def getNext(self, num):
+        total_sum = 0
+        while num > 0:
+            num, digit = divmod(num, 10)
+            total_sum += digit ** 2
+        return total_sum