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题目
The distance of a pair of integers a and b is defined as the absolute difference between a and b.
Given an integer array nums and an integer k, return the kth smallest distance among all the pairs nums[i] and nums[j] where 0 <= i < j < nums.length.
Example 1:
Input: nums = [1,3,1], k = 1
Output: 0
Explanation: Here are all the pairs:
(1,3) -> 2
(1,1) -> 0
(3,1) -> 2
Then the 1st smallest distance pair is (1,1), and its distance is 0.
Example 2:
Input: nums = [1,1,1], k = 2
Output: 0
Example 3:
Input: nums = [1,6,1], k = 3
Output: 5
Constraints:
- n == nums.length
- 2 <= n <= 104
- 0 <= nums[i] <= 106
- 1 <= k <= n * (n - 1) / 2
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代码
class Solution {
public:
int smallestDistancePair(vector<int>& nums, int k) {
sort(nums.begin(), nums.end());
int low = 0, high = 100000000;
while(low < high)
{
int mid = (low + high) / 2, count = 0;
for(int i = 0, j = i+1; i < nums.size(); i++)
{
while(j < nums.size() && nums[j] - nums[i] <= mid) j++;
count += j - i - 1;
}
if(count < k)
{
low = mid+1;
}
else
{
high = mid;
}
}
return high;
}
};