[Swift]LeetCode448.找到所有数组中消失的数字|FindAllNumbersDisappearedinanArray ...

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› 移动开发›Swift 教程

原作者: [db:作者] 来自: [db:来源] 收藏邀请

★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★
➤微信公众号：山青咏芝（shanqingyongzhi）
➤博客园地址：山青咏芝（https://www.cnblogs.com/strengthen/）
➤GitHub地址：https://github.com/strengthen/LeetCode
➤原文地址：https://www.cnblogs.com/strengthen/p/9790831.html
➤如果链接不是山青咏芝的博客园地址，则可能是爬取作者的文章。
➤原文已修改更新！强烈建议点击原文地址阅读！支持作者！支持原创！
★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★

热烈欢迎，请直接点击！！！

进入博主App Store主页，下载使用各个作品！！！

注：博主将坚持每月上线一个新app！！！

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]

给定一个范围在 1 ≤ a[i] ≤ n ( n = 数组大小 ) 的整型数组，数组中的元素一些出现了两次，另一些只出现一次。

找到所有在 [1, n] 范围之间没有出现在数组中的数字。

您能在不使用额外空间且时间复杂度为O(n)的情况下完成这个任务吗? 你可以假定返回的数组不算在额外空间内。

示例:

输入:
[4,3,2,7,8,2,3,1]

输出:
[5,6]

80ms

 1 class Solution {
 2     func findDisappearedNumbers(_ nums: [Int]) -> [Int] {
 3         
 4         var input = nums
 5         var result: [Int] = []
 6         
 7         for i in 0..<input.count{
 8             var check = -1
 9             
10             if input[i] > 0{
11                 check = input[i] - 1
12             }else{
13                 check = (input[i] * (-1)) - 1
14             }
15             
16             if input[check] > 0{
17                 input[check] = (input[check] * (-1))
18             }
19             
20         }
21         
22         for i in 0..<input.count{
23             if input[i] > 0 {
24                 result.append(i+1)
25             }
26         }
27         
28         return result
29     }
30 }

88ms

 1 class Solution {
 2     func findDisappearedNumbers(_ nums: [Int]) -> [Int] {
 3         var list = nums
 4         var results = [Int]()
 5 
 6         for i in 0 ..< list.count {
 7             let idx = abs(list[i]) - 1
 8             list[idx] = (list[idx] > 0) ? -list[idx] : list[idx]
 9         }
10 
11         for i in 0 ..< list.count {
12             if (0 < list[i]) {
13                 results.append(i + 1)
14             }
15         }
16 
17         return results
18     }
19 }

104ms

 1 class Solution {
 2     func findDisappearedNumbers(_ nums: [Int]) -> [Int] {
 3         let test = 0
 4         if test == 0 {        
 5             var result = [Int]()
 6             var explored = [Bool](repeating: false, count: nums.count+1)
 7 
 8             for num in nums {
 9                 explored[num] = true
10             }
11 
12             var i = 1
13             while i < explored.count {
14                 if explored[i] == false {
15                     result.append(i)
16                 }
17 
18                 i += 1
19             }
20 
21             return result
22         }
23         
24         if test == 1 {        
25             var result = [Int]()
26             var nums = nums
27 
28             var i = 0
29             while i < nums.count {
30                 while nums[i] != nums[nums[i]-1] {
31                     nums.swapAt(i, nums[i]-1)
32                 }
33 
34 
35                 i += 1
36             }
37 
38             var j = 0
39             while j < nums.count {
40                 if j+1 != nums[j] {
41                     result.append(j+1)
42                 }
43 
44                 j += 1
45             }
46 
47             return result
48         }
49     }
50 }

112ms

 1 class Solution {
 2     func findDisappearedNumbers(_ nums: [Int]) -> [Int] {
 3         var nums = nums
 4         for idx in 0..<nums.count {
 5             let nextIdx = abs(nums[idx]) - 1
 6             nums[nextIdx] = nums[nextIdx] < 0 ? nums[nextIdx] : -nums[nextIdx]
 7         }
 8         var ans = [Int]()
 9         for idx in 0..<nums.count {
10             if nums[idx] > 0 {
11                 ans.append(idx + 1)
12             }
13         }
14         return ans
15     }
16 }

124ms

 1 class Solution {
 2     func findDisappearedNumbers(_ nums: [Int]) -> [Int] {
 3         var nums = nums
 4 
 5         for i in 0..<nums.count {
 6             if nums[abs(nums[i]) - 1] > 0 {
 7                 nums[abs(nums[i]) - 1] *= -1
 8             }
 9         }
10 
11         var res = [Int]()
12 
13         for i in 0..<nums.count {
14             if nums[i] > 0 {
15                 res.append(i + 1)
16             } else {
17                 nums[i] *= -1
18             }
19         }
20 
21         return res
22     }
23 }