# 41 缺失的第一个正数

class Solution {
    public int firstMissingPositive(int[] nums) {
        if (nums.length == 0) {
            return 1;
        }

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

        for (int i = 1; i < temp.length; i++) {
            if (temp[i] != i) {
                return i;
            }
        }
        return temp.length;
    }
}