leetcode-go/leetcode/easy/38.go

package main

// iterator of countAndSay function
func casIter(last string, n int) string {
	if n == 1 {
		return last
	}
	next := make([]rune, 0)
	curr := last[0]
	cnt := 1
	for i := 1; i < len(last); i++ {
		if curr != last[i] {
			next = append(next, rune(cnt+'0'), rune(curr))
			curr = last[i]
			cnt = 1
		} else {
			cnt++
		}
	}
	next = append(next, rune(cnt+'0'), rune(curr))
	return casIter(string(next), n-1)
}

func countAndSay(n int) string {
	return casIter("1", n)
}