题解 | #在旋转过的有序数组中寻找目标值#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param nums int整型一维数组 
     * @param target int整型 
     * @return int整型
     */
    public int search (int[] nums, int target) {
        // write code here
        if (nums == null || nums.length < 1) {
            return -1;
        }
        int n = nums.length;
        int l = 0;
        int r = n - 1;
        int mid;
        while (l <= r) {
            mid = l + (r - l) / 2;
            if (nums[mid] == target) {
                return mid;
            }
            // 在前半段
            if (nums[l] <= nums[mid]) {
                if (nums[l] <= target && target < nums[mid]) {
                    r = mid - 1;
                } else {
                    l = mid + 1;
                }
            } else {
                if (nums[mid] < target && target <= nums[r]) {
                    l = mid + 1;
                } else {
                    r = mid - 1;
                }
            }
        }
        return -1;
    }
}