package helper func maxInt(x, y int) int { if x > y { return x } return y } func minInt(x, y int) int { if x < y { return x } return y } func list2str(head *ListNode) string { curr := head str := make([]rune, 0) for curr != nil { str = append(str, rune(curr.Val+'0')) curr = curr.Next } return string(str) }