【leetcode】127. Word Ladder

var isExist  =  false
var minLen   = 0
var target   = ""
func ladderLength(beginWord string, endWord string, wordList []string) int {
    minLen = len(wordList)
    target = endWord
    bfs(1, beginWord, wordList)
    if isExist == false {
        minLen = 0
    }

    return  minLen
}

func bfs(curLen int, curStr string, remainList []string) {
    for i, remainStr := range remainList {
        diffNum := 0
        for j, curCh := range curStr {
            if byte(curCh) != byte(remainStr[j]) {
                diffNum++
            }

            if diffNum > 1 {
                break
            }
        }

        if target == curStr {
            isExist = true
            if minLen > curLen {
                minLen = curLen
                return
            }
        }

        if diffNum == 1 {
            bfs(curLen + 1, remainStr, append(remainList[:i], remainList[i+1:]...))
        }
    }
}