Java solution using HashMap and Hashset
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: O(N)\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity: O(N)\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\n    public int winningPlayerCount(int n, int[][] pick) {\n\n        HashMap<String, Integer> map = new HashMap<>();\n        HashSet<Integer> ans = new HashSet<>();\n        for (int i = 0; i < pick.length; i++) {\n            \n            if(pick[i][0] == 0) {\n                ans.add(pick[i][0]);\n                continue;\n            }\n            if(map.containsKey(pick[i][0] + "@" +  pick[i][1])) {\n                if(map.get(pick[i][0] + "@" +  pick[i][1]) == pick[i][0]) {\n                    ans.add(pick[i][0]);\n                }\n            }\n\n        map.put(pick[i][0] + "@" +  pick[i][1], map.getOrDefault(pick[i][0] + "@" +  pick[i][1], 0) + 1);\n        }\n\n        return ans.size();\n    }\n}\n```
['Java']