LeetCode 34. 在排序数组中查找元素的第一个和最后一个位置
题目链接
与剑指 Offer 53 - I. 在排序数组中查找数字 I一样(仅返回值不同)
class Solution {
public:
vector<int> searchRange(vector<int>& nums, int target) {
std::ios::sync_with_stdio(false);
if(nums.empty()) return {-1, -1};
int l = 0, r = nums.size() - 1;
while(l < r){
int mid = (l + r) / 2;
if(nums[mid] >= target) r = mid;
else l = mid + 1;
}
if(nums[l] != target) return {-1, -1};
else{
int res = l;
l = 0, r = nums.size() - 1;
while(l < r){
int mid = (l + r + 1) / 2;
if(nums[mid] <= target) l = mid;
else r = mid - 1;
}
return {res, l};
}
}
};