leetcode--539. Minimum Time Difference

const MaxMinute = 24 * 60

func findMinDifference(slice1 []string) int {
    min := MaxMinute

    ts := make([]int, 2*MaxMinute)
    for _, v := range slice1 {
        ts[getMinute(v)] ++
        if ts[getMinute(v)]==2{
            return 0
        }
        ts[getMinute(v)+MaxMinute]++
    }


    front, rear := 0, 0
    for front < MaxMinute*2 {
        if front == rear || ts[front] == 0 {
            front++
            continue
        }
        if ts[rear] == 0 {
            rear++
            continue
        }

        if min > front-rear {
            min = front - rear
        }
        rear = front
        front ++
    }

    return min
}

func getMinute(timestr string) int {
        return ((int(timestr[0]-‘0‘))*10+int(timestr[1]-‘0‘))*60+(int(timestr[3]-‘0‘))*10+int(timestr[4]-‘0‘)
}