// Package q3713 implements a solution for https://leetcode.com/problems/longest-balanced-substring-i/
package q3713

func longestBalanced(s string) int {
	longest := 0
	cnt, tmp := [26]int{}, [26]int{}

	for i := range len(s) {
		copy(cnt[:], tmp[:])
		distinct, imbal, maxCnt := 0, 0, 0

		for j := i; j >= 0; j-- {
			c := s[j] - 'a'
			cnt[c]++
			if cnt[c] == 1 {
				distinct++
				imbal++
			}

			if cnt[c] > maxCnt {
				maxCnt = cnt[c]
				imbal = distinct - 1
			} else if cnt[c] == maxCnt {
				imbal--
			}

			if imbal == 0 {
				longest = max(longest, i-j+1)
			}
		}
	}

	return longest
}

var _ = longestBalanced