排序数组（旋转）查找数字

搜索旋转排序数组

不包含重复元素

33. 搜索旋转排序数组

class Solution {

    public int search(int[] nums, int target) {
        int low = 0;
        int high = nums.length - 1;
        while (low <= high) {
            int mid = low + ((high - low) >> 1);
            if (nums[mid] == target) {
                return mid;
            }
            if (nums[0] <= nums[mid]) {
                if (nums[0] <= target && target < nums[mid]) {
                    high = mid - 1;
                } else {
                    low = mid + 1;
                }
            } else {
                if (nums[mid] < target && target <= nums[nums.length - 1]) {
                    low = mid + 1;
                } else {
                    high = mid - 1;
                }
            }
        }
        return -1;
    }
    
}

包含重复元素

81. 搜索旋转排序数组 II

不包含重复元素

153. 寻找旋转排序数组中的最小值

class Solution {
    public int findMin(int[] nums) {
        int low = 0;
        int high = nums.length - 1;
        while (low < high) {
            if (nums[low] <= nums[high]) {
                return nums[low];
            }
            int mid = low + ((high - low) >> 1);
            if (nums[low] <= nums[mid]) {
                low = mid + 1;
            } else {
                high = mid;
            }
        }
        return nums[low];
    }
}

包含重复元素

154. 寻找旋转排序数组中的最小值 II

剑指 Offer 11. 旋转数组的最小数字

class Solution {
    public int findMin(int[] numbers) {
        int low = 0;
        int high = numbers.length - 1;
        while (low < high) {
            int pivot = low + (high - low) / 2;
            if (numbers[pivot] < numbers[high]) {
                high = pivot;
            } else if (numbers[pivot] > numbers[high]) {
                low = pivot + 1;
            } else {
                high -= 1;
            }
        }
        return numbers[low];
    }
}

排序数组中元素的第一个和最后一个位置

参考：《剑指offer》系列 数字在排序数组中出现的次数（Java）