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Search.java
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31 lines (24 loc) · 950 Bytes
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/**
* 33 搜索旋转排序数组 https://leetcode-cn.com/problems/search-in-rotated-sorted-array/
*/
public class Search {
public static void main(String[] args) {
System.out.println(new Search().search(new int[]{4, 5, 6, 7, 0, 1, 2}, 0));
}
/**
* 中心思想： 判断target在 mid左边还是右边，就可以直接使用二分查找进行搜索。
* 本体在if中列举了 所有可能在mid左边的情况
*/
public int search(int[] nums, int target) {
int left = 0;
int right = nums.length - 1;
while (left <= right) {
int mid = left + (right - left) / 2;
if (nums[mid] == target) return mid;
else if ((nums[left] > nums[mid] && (target >= nums[left] || target < nums[mid])) || (target >= nums[left] && target < nums[mid])) {
right = mid - 1;
} else left = mid + 1;
}
return -1;
}
}