/**
 * Created by wqc on 2017/7/18.
 * 查找旋轉數組的最小數字
 * 把一個數組最開始的若幹個元素搬到數組的末尾，稱為數組的旋轉
 * 輸入一個遞增排序的數組的一個旋轉，輸出旋轉數組的最小元素
 * 如：3,4,5,1,2  為1,2,3,4,5的一個旋轉，最小值為1
 */
public class Problem8_findMinNumber {
    public Integer findMinNum(int[] array)
    {
        if(array == null)
        {
            return null;
        }

        int leftIndex = 0;
        int rightIndex =array.length-1;
        int mid = 0;
        while(array[leftIndex]>=array[rightIndex])
        {
            if(rightIndex-leftIndex <= 1)
            {
                mid = rightIndex;
                break;
            }

            mid = (leftIndex + rightIndex)/2;
            if(array[leftIndex] == array[rightIndex] && array[leftIndex] == array[mid])
            {
                if(array[leftIndex + 1] != array[rightIndex - 1])
                {
                    mid = array[leftIndex + 1] < array[rightIndex -1] ? (leftIndex + 1) : (rightIndex - 1);
                    break;
                }else{
                    leftIndex++;
                    rightIndex--;
                }
            }else if(array[mid] >= array[leftIndex]){

                leftIndex = mid;
            }else if(array[mid] <= array[rightIndex]){

                rightIndex = mid;
            }
        }
        return array[mid];
    }

}

劍指offer java -查找旋轉數組的最小數字