面试题8：旋转数组的最小数字

//面试题8：旋转数组的最小数字

 

//递增排序的{1,2,3,4,5}----->旋转为 {3,4,5,1,2}

//求最小的数字

 

 

package com.hb.jzoffer;



import offer.utilities.ArrayUtils;



//面试题8：旋转数组的最小数字



//{1,2,3,4,5}----->旋转为 {3,4,5,1,2}

publicclass MinNumberInRotatedArray_8 {

public  int  Min(int[] array ) throws Exception{

        int  length = array.length ;

        if(length < 0){

            Exception e = new Exception();

            throw e;

        }

        int  index1 = 0 ; 

        int  index2 = length - 1;

        int  indexMid = index1 ; //如果下面while循环里面的不成立，说明数组是有序的，没有旋转，所以indexMid初始化为Index1

        while(array[index1] >= array[index2]){

            if(index2 - index1 == 1){

                indexMid = index2;

                break ;

            }

            indexMid = (index1 + index2) / 2 ;

            

            //如果下标为index1 、index2 和 indexMid 指向的三个数字相等，

            //则只能用书序查找

            if(array[index1] == array[index2] && array[indexMid] == array[index1]){

                return MinInOrder(array , index1 , index2);                

            }

            

            if(array[indexMid] >= array[index1]){

                index1 = indexMid ;

            }else if(array[indexMid] <= array[index2]){

                index2 = indexMid ;

            }    

        }

        

        return array[indexMid];    

        

    }

    

    public int MinInOrder(int[] array , int index1 , int index2){

        int  result = array[index1];

        for(int i = index1 + 1 ; i <= index2 ; i++){

            if(result > array[i]){

                result = array[i] ;

            }            

        }        

        return result;

    }

    

    public static void main(String[] args) throws Exception {

        int[] array = {3,4,5,1,2};

        int[] array1 = {1,1,1,0,1};

        MinNumberInRotatedArray_8 findMid = new MinNumberInRotatedArray_8();

        int min = findMid.Min(array);

        int min1 = findMid.Min(array1);

        ArrayUtils.printArray(array);

        System.out.println(min);

        ArrayUtils.printArray(array1);

        System.out.println(min1);

        

    }

    

    



}