92: Square digit chains

92_square_digit_chains/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func main() {
+	count := 0
+	for i := 1; i < 10000000; i++ {
+		if goChain(i) {
+			count++
+		}
+	}
+	fmt.Println(count)
+}
+
+func goChain(n int) bool {
+	s := strconv.Itoa(n)
+	sum := 0
+	for _, c := range s {
+		i, _ := strconv.Atoi(string(c))
+		sum += i * i
+	}
+	if sum == 89 {
+		return true
+	} else if sum == 1 {
+		return false
+	}
+	return goChain(sum)
+}