leetcode 442. Find All Duplicates in an Array(找出出现两次的元素)

2017年4月12日 0 作者 CrazyKK

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?


和leetcode 448是一对题目。