Leecode1124表现良好的最长时间段

class Solution {
    public int longestWPI(int[] hours) {
        if(hours == null || hours.length == 0){
            return 0;
        }
        int[] transferArray = new int[hours.length];
        int[] goodDay = new int[hours.length+1];
        goodDay[0]=0;
        int max = 0;
        for(int i=0;i<transferArray.length;++i){
            if(transferArray[i]>8){
                max = 1;
            }
            transferArray[i]=hours[i]>8?1:-1;
            goodDay[i+1]=goodDay[i]+transferArray[i];
        }
        Stack<Integer> stack = new Stack();
        for(int i=0;i<goodDay.length;++i){
            if(stack.isEmpty()){
                stack.push(i);
            }else {
                if(goodDay[i]<goodDay[stack.peek()]){
                    stack.push(i);
                }
            }
        }
        for(int i=goodDay.length-1;i>=0;--i){
            int last = i;
            while(!stack.isEmpty() && goodDay[i]>goodDay[stack.peek()]){
                last = stack.pop();
            }
            if(last != i){
                if(i-last > max){
                    max = i-last;
                }
            }
        }
        return max;
    }
}