Two Out of Three.cpp

class Solution {
public:
    vector<int> twoOutOfThree(vector<int>& nums1, vector<int>& nums2, vector<int>& nums3) {
        vector<int>f(110, 0);
        for (int n : nums1) f[n] |= 1<<0;
        for (int n : nums2) f[n] |= 1<<1;
        for (int n : nums3) f[n] |= 1<<2;
        
        vector<int>ret;
        for (int i = 1; i <= 100; i++) if (f[i] == 3 || f[i] >= 5) ret.push_back(i);
        return ret;
    }
};