【leetcode刷题笔记】Search in Rotated Sorted Array II

时间:2023-03-08 22:41:03

Follow up for "Search in Rotated Sorted Array":
What if duplicates are allowed?

Would this affect the run-time complexity? How and why?

Write a function to determine if a given target is in the array.


题解:如果没有重复的元素,那么就可以根据target是否在某一半而扔掉另外一半。但是如果有重复的元素,就有可能不知道往哪边跳转:

例如A = {1,3,3,3,3,3},经过变换后得到数组{3,1,3,3,3,3},此时A[mid] = 3 = A[left] = A[right],如果target = 1,两边都不能扔,所以不能用二分的方法。

直接用遍历O(n)的方法也可以AC:

 public class Solution {
public boolean search(int[] A, int target) {
if(A == null || A.length == 0)
return false;
for(int i = 0;i < A.length;i++)
if(target == A[i])
return true;
return false;
}
}