LeetCode 448.Find All Numbers Disappeared in an Array

本文主要是介绍LeetCode 448.Find All Numbers Disappeared in an Array，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

LeetCode 448.Find All Numbers Disappeared in an Array

Description:

Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once.
Find all the elements of [1, n] inclusive that do not appear in this array.
Could you do it without extra space and in O(n) runtime? You may assume the returned list does not count as extra space.

Example:

Input: [4,3,2,7,8,2,3,1]
Output: [5,6]

分析：

hash[i]用来标记i是否在nums数组中出现过，然后判断hash[i]的真假将没有出现过的放入res数组中，返回res数组

代码如下：

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
class Solution {
public:vector<int> findDisappearedNumbers(vector<int>& nums) {vector<int> res;vector<bool> hash(nums.size() + 1, false);for (int i = 0; i < nums.size(); i++) {hash[nums[i]] = true;}for (int i = 1; i < hash.size(); i++) {if (hash[i] == false) {res.push_back(i);}}return res;}
};
int main() {Solution s;int n;cin >> n;vector<int> nums(n);for (int i = 0; i < n; i++) {cin >> nums[i];}vector<int> temp = s.findDisappearedNumbers(nums);for (int i = 0; i < temp.size(); i++) {cout << temp[i] << " ";}return 0;
}

这篇关于LeetCode 448.Find All Numbers Disappeared in an Array的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---