No Matrix || Set || C++
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\npublic:\n   set<pair<int,int>> s;\n    int r , c; \n    Solution(int m, int n) \n    {\n        \n        r = m ; \n        c = n ; \n    }\n    \n    vector<int> flip() \n    {\n        int x = rand()%r; \n        int y = rand()%c; \n        if(s.find({x,y})==s.end())\n        {    s.insert({x,y});\n            return {x,y};\n        }\n        else return flip();\n    }\n    \n    void reset() \n    {\n         s.clear(); \n    }\n};\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution* obj = new Solution(m, n);\n * vector<int> param_1 = obj->flip();\n * obj->reset();\n */\n```
['C++']