Press "Enter" to skip to content

Huahua's Tech Road

花花酱 LeetCode 422. Find All Duplicates in an Array

Given an array of integers, 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once.

Find all the elements that appear twice in this array.

Could you do it without extra space and in O(n) runtime?



花花酱 LeetCode 128. Longest Consecutive Sequence

Given an unsorted array of integers, find the length of the longest consecutive elements sequence.

For example,
Given [100, 4, 200, 1, 3, 2],
The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4.

Your algorithm should run in O(n) complexity.


花花酱 Leetcode 371. Sum of Two Integers

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.


[ZOJ] 3612: Median


[ZOJ] 3713: In 7-bit