Leet Code Daily 2024-05-02 - Largest Positive Integer That Exists With Its Negative

constexpr int kMaxNum = 1000;

class Solution {
public:
    int findMaxK(vector<int>& nums) {
        bool has_pos[kMaxNum + 1] = { false };
        bool has_neg[kMaxNum + 1] = { false };
        for (const auto& x : nums) {
            if (x >= 0) {
                has_pos[+x] = true;
            }
            if (x <= 0) {
                has_neg[-x] = true;
            }
        }
        for (int i = kMaxNum; i >= 0; i--) {
            if (has_pos[i] && has_neg[i]) {
                return i;
            }
        }
        return -1;
    }
};