448. Find All Numbers Disappeared in an Array

JIAKAOBO

LeetCode

感谢赞助!

• ㊗️
• 大家
• offer
• 多多！

Problem

Given an array nums of n integers where nums[i] is in the range [1, n], return an array of all the integers in the range [1, n] that do not appear in nums.

Example 1:

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

Example 2:

Input: nums = [1,1]
Output: [2]

Code

参考 442

class Solution {
    public List<Integer> findDisappearedNumbers(int[] nums) {
        for(int i = 0; i < nums.length; i++) {
            int index = Math.abs(nums[i]) - 1;
            if(nums[index] > 0) {
                nums[index] = -nums[index];
            }
        }

        List<Integer> res = new ArrayList<>();

        for(int i = 0; i < nums.length; i++) {
            if(nums[i] > 0) {
                res.add(i + 1);
            }
        }

        return res;
    }
}