Class Solution


  • public class Solution
    extends Object
    41 - First Missing Positive.

    Hard

    Given an unsorted integer array nums, return the smallest missing positive integer.

    You must implement an algorithm that runs in O(n) time and uses constant extra space.

    Example 1:

    Input: nums = [1,2,0]

    Output: 3

    Example 2:

    Input: nums = [3,4,-1,1]

    Output: 2

    Example 3:

    Input: nums = [7,8,9,11,12]

    Output: 1

    Constraints:

    • 1 <= nums.length <= 5 * 105
    • -231 <= nums[i] <= 231 - 1
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • firstMissingPositive

        public int firstMissingPositive​(int[] nums)