给你一个按照非递减顺序排列的整数数组 nums，和一个目标值 target。请你找出给定目标值在数组中的开始位置和结束位置。
如果数组中不存在目标值 target，返回 [-1, -1]。
你必须设计并实现时间复杂度为 O(log n) 的算法解决此问题。
示例 1：
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| 输入：nums = , target = 8
输出：
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示例 2：
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| 输入：nums = , target = 6
输出：
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示例 3：
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| 输入：nums = , target = 0
输出：
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提示：
0 <= nums.length <= 105-109 <= nums[i] <= 109nums 是一个非递减数组-109 <= target <= 109
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| class Solution {
public int[] searchRange(int[] nums, int target) {
int leftBorder = searchLeft(nums, target);
int rightBorder = searchRight(nums, target);
return new int[]{leftBorder, rightBorder};
}
public int searchLeft(int[] nums, int target){
int left = 0;
int right = nums.length - 1;
int leftBorder = -1;
while(left <= right){
int mid = (left + right) >> 1;
if(nums[mid] < target){
left = mid + 1;
}else if(nums[mid] > target){
right = mid - 1;
}else if(nums[mid] == target){
leftBorder = mid;
right = mid - 1;
}
}
return leftBorder;
}
public int searchRight(int[] nums, int target){
int left = 0;
int right = nums.length - 1;
int rightBorder = -1;
while(left <= right){
int mid = (left + right) >> 1;
if(nums[mid] < target){
left = mid + 1;
}else if(nums[mid] > target){
right = mid - 1;
}else if(nums[mid] == target){
rightBorder = mid;
left = mid + 1;
}
}
return rightBorder;
}
}
|