Given a sorted array of integers, find the starting and ending position of a given target value.
Your algorithm's runtime complexity must be in the order of O(log n).
If the target is not found in the array, return [-1, -1]
.
For example,
Given [5, 7, 7, 8, 8, 10]
and target value 8,
return [3, 4]
.
在有序数组中找出指定元素存在的区间。
两次二分,找到等于target和大于target的位置就行了
代码语言:javascript复制class Solution {
public:
vector<int> searchRange(vector<int>& nums, int target) {
vector<int> result(2,-1);
int l=lower_bound(nums.begin(),nums.end(),target)-nums.begin();
int r=upper_bound(nums.begin(),nums.end(),target)-nums.begin();
if(l!=r)
{
result[0]=l;
result[1]=r-1;
}
return result;
}
};