关于golang:leetcode-401-组合问题

func readBinaryWatch(turnedOn int) []string {
    if turnedOn >= 9 {//panic("不能正确示意")
        return []string{}
    }
    maxHnum := 3
    maxMnum := 5
    returnData := make([]string, 0, 255)
    for hourNum, minuteNum := 0, 0; hourNum <= maxHnum; hourNum++ {
        minuteNum = turnedOn - hourNum
        if (minuteNum < 0) {break;}
        if minuteNum >maxMnum {continue}
        hourList := getHour(hourNum)
        minuteList := getMinute(minuteNum)

        for _, h := range hourList {
            for _, m := range minuteList {returnData = append(returnData, h + ":" + m)
            }
        } 
        
    }
    return returnData
}

func getMinute(n int) []string {if (n == 0) {return []string{"00"}
    }
    cSet := []int{1, 2, 4, 8, 16, 32}
    num := make([]string, 0, 60)

    list := sumNumItem(cSet, n)
    for _, v := range list {
        if v > 59 {continue}
        num = append(num, fmt.Sprintf("%02d", v))
    }
    return num
}

func getHour(n int) []string {if (n == 0) {return []string {"0"}
    }
    cSet := []int{1, 2, 4, 8}

    num := make([]string, 0, 60)
    list := sumNumItem(cSet, n)

    for _, v := range list {
        if v > 11 {continue}
        num = append(num, fmt.Sprintf("%d", v))
    }
    return num
}

func sumNumItem(list []int, num int) []int {l := len(list)
    if num > l {//panic("求和数量异样")
        return []int{}
    }

    if num == 1 {return list}

    returnData := make([]int, 0, 60)
    // 应用位图对应形式，顺次确认站位组合
    indexList := make([]int, l)
    for i := 0; i < num; i++ {indexList[i] = 1
    }
    returnData = append(returnData, sumIdxNum(list, indexList))
    for {
        find := false
        for i := 0; i < l - 1; i++ {if (indexList[i] == 1 && indexList[i + 1] == 0) {
                find = true
                indexList[i], indexList[i + 1] = 0, 1
                if indexList[0] == 0 && i > 1 {resetZeroIdx(indexList, i)
                }
                returnData = append(returnData, sumIdxNum(list, indexList))
                break
            }

        }
        if !find {break}
    }
    return returnData
}

func sumIdxNum(list []int, idxSet []int) int {
    num := 0
    for idx, b := range idxSet {
        if b == 1 {num += list[idx]
        }
    }
    return num
}

func resetZeroIdx(idxList []int, k int) {
    sum := 0
    for i := 0; i < k; i++ {if idxList[i] == 1 {sum++}
    }
    // 将前 sum 个改为 1，之后的改为 0
    for i := 0; i < k; i++ {
        if i < sum {idxList[i] = 1
        } else {idxList[i] = 0
        }
    }
}