JavaArithmetic/src/LeetCode/LeetCode220.java at master · feinibuai/JavaArithmetic · GitHub

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package LeetCode;

import java.util.TreeSet;

public class LeetCode220 {

// 220. Contains Duplicate III

// https://leetcode.com/problems/contains-duplicate-iii/description/

// 时间复杂度: O(nlogk)

// 空间复杂度: O(k)

public static boolean containsNearbyAlmostDuplicate(int[] nums, int k, int t) {

// 这个问题的测试数据在使用int进行加减运算时会溢出

// 所以使用long long

TreeSet<Long> record = new TreeSet<Long>();

// nums = [1,2,3,1], k = 3, t = 0 true

// nums = [1,5,9,1,5,9], k = 2, t = 3 false

for (int i = 0; i < nums.length; i++) {

// ceiling 向上取整,ceiling会去查找在set中有没有该值，如果没有--->null

if (record.ceiling((long) nums[i] - (long) t) != null &&

record.ceiling((long) nums[i] - (long) t) <= (long) nums[i] + (long) t)

return true;

record.add((long) nums[i]);

if (record.size() == k + 1)

record.remove((long) nums[i - k]);

}

return false;

}

public static void main(String[] args) {

int[] nums = {1, 3, 2, 1};

int k = 3, t = 0;

containsNearbyAlmostDuplicate(nums, k, t);

}