Leetcode 442. Find All Duplicates in an Array | | Leetcode 442. Find All Duplicates in an Array 文章作者:Tyan博客:noahsnail.com | CSDN | 简书 1. Description 2. Solution O(n), O(n) 12345678910111213141516171819class Solution {public: vector<int> findDuplicates(vector<int>& nums) { vector<int> result; if(0 == nums.size()) { return result; } int flag[nums.size()] = {0}; for(int i = 0; i < nums.size(); i++) { if(flag[nums[i]]) { result.push_back(nums[i]); } else { flag[nums[i]] = 1; } } return result; }}; O(n), O(1) 1234567891011121314151617class Solution {public: vector<int> findDuplicates(vector<int>& nums) { vector<int> result; if(0 == nums.size()) { return result; } for(int i = 0; i < nums.size(); i++) { int index = abs(nums[i]) - 1; if(nums[index] < 0) { result.push_back(abs(nums[i])); } nums[index] = - nums[index]; } return result; }}; Reference https://leetcode.com/problems/find-all-duplicates-in-an-array/description/ 如果有收获,可以请我喝杯咖啡! 赏 微信打赏 支付宝打赏