在有序旋转数组中找到一个数

我就是我 2022-05-27 10:40 143阅读 0赞

![这里写图片描述][70]

//在有序旋转数组中找到一个数
    public class FindNum{
    
         public static boolean isContains(int[]arr,int num)
         {
              int low=0;
              int high=arr.length-1;
              int mid=0;
              while(low<=high)
              {
                  mid=(low+high)/2;
                  if(arr[mid]==num)
                  {
                      return true;
                  }
                  if(arr[low]==arr[mid]&&arr[mid]==arr[high])
                  {
                        while(low!=mid&&arr[low]==arr[mid])
                        {
                             low++;
                        }
                        if(low==mid)
                        {
                              low=mid+1;
                              continue;
                        }
    
                  }
                  if(arr[low]!=arr[mid])
                  {
                      if(arr[mid]>arr[low])
                      {
                           if(num>=arr[low]&&num<arr[mid])
                           {
                              high=mid-1;
                           }else{
                               low=mid+1;
                           }
                      }else{
                             if(num>arr[mid]&&num<=arr[high])
                             {
                                 low=mid+1;
                             }else{
                                 high=mid-1;
                             }
                      }
                  }else{
    
                        if(arr[mid]<arr[high])
                        {
                              if(num>arr[mid]&&num<=arr[high])
                              {
                                    low=mid+1;
                              }else{
                                     high=mid-1;
                              }
                        }else{
    
                               if(num>=arr[low]&&num<arr[mid])
                               {
                                 high=mid-1;
                               }else{
                                  low=mid+1;
                               }
    
                        }
                  }
              }
              return false;
         }
    
         public static  void main(String[]args)
         {
            //System.out.println("Hello");
             int arr[]={
       4,5,6,7,1,2,3};
             int num=3;
             System.out.println(isContains(arr,num));
         }
    }

![这里写图片描述][70 1]

[70]: /images/20220527/e3e9ec791b3043489c8b3135c1ffeba4.png
[70 1]: /images/20220527/90e01ca184d247709fc98513b779761f.png