Given an integer array, return the k-th smallest distance among all the pairs. The distance of a pair (A, B) is defined as the absolute difference between A and B.
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.
Note:
2 <= len(nums) <= 10000.0 <= nums[i] < 1000000.1 <= k <= len(nums) * (len(nums) - 1) / 2.struct Solution;
impl Solution {
fn smallest_distance_pair(mut nums: Vec<i32>, k: i32) -> i32 {
let n = nums.len();
nums.sort_unstable();
let mut lo = 0;
let mut hi = nums[n - 1] - nums[0];
while lo < hi {
let mi = lo + (hi - lo) / 2;
let mut count = 0;
let mut j = 1;
for i in 0..n - 1 {
while j < n && nums[j] - nums[i] <= mi {
j += 1;
}
count += j - 1 - i;
}
if count >= k as usize {
hi = mi;
} else {
lo = mi + 1;
}
}
lo
}
}
#[test]
fn test() {
let nums = vec![1, 3, 1];
let k = 1;
let res = 0;
assert_eq!(Solution::smallest_distance_pair(nums, k), res);
let nums = vec![62, 100, 4];
let k = 2;
let res = 58;
assert_eq!(Solution::smallest_distance_pair(nums, k), res);
}