// Package q696 implements a solution for https://leetcode.com/problems/count-binary-substrings/
package q696

func countBinarySubstrings(s string) int {
	cnt := 0
	last := byte('0')
	lastLen, curLen := 0, 0
	for i := range len(s) {
		if s[i] != last {
			last, lastLen = s[i], curLen
			curLen = 0
		}
		curLen++
		if curLen <= lastLen {
			cnt++
		}
	}
	return cnt
}

var _ = countBinarySubstrings