public class E11RotateInOrderNumbers {
    //寻找某数组旋转数组中最小数字
    //特殊情况：移动0个元素；数组中存在重复的数字

    public static int getMin(int[] numbers, int length){
        if (numbers == null || length <= 0)
            throw new IllegalArgumentException("Invalid Input");

        int startIndex = 0;
        int endIndex = length - 1;
        int midIndex = startIndex;
        while(numbers[startIndex] >= numbers[endIndex]){
            //循环终止条件
            if (endIndex == startIndex + 1)
                return numbers[endIndex];

            //三个指针相等时遍历数组寻找
            if (numbers[startIndex] == numbers[midIndex]
                    && numbers[midIndex] == numbers[endIndex])
                return findMin(numbers, startIndex, endIndex);

            midIndex = (startIndex + endIndex) / 2;
            if (numbers[midIndex] >= numbers[startIndex])
                startIndex = midIndex;
            else if (numbers[midIndex] <= numbers[endIndex])
                endIndex = midIndex;

        }
        //移动0个元素直接返回数组第一个数字
        return midIndex;
    }

    private static int findMin(int[] numbers, int startIndex, int endIndex){
        //遍历寻找
        int minNumber = numbers[startIndex];
        for (int i = startIndex; i <= endIndex; i++){
            if (numbers[i] < minNumber)
                minNumber = numbers[i];
        }
        return minNumber;
    }
}