Array of Doubled Pairs LeetCode solution in C++

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class Solution {
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 public:
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  bool func(vector<int> pos) {
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    map<int, int> mp;
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    for (int i = 0; i < pos.size(); i++) {
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      mp[pos[i]]++;
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    }
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    for (auto it : mp) {
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      if (mp.find(2 * it.first) == mp.end()) {
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        return false;
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      }
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      if (mp[it.first] > mp[2 * it.first]) {
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        return false;
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      }
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      mp[2 * it.first] -= mp[it.first];
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      if (mp[2 * it.first] == 0) mp.erase(2 * it.first);
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    }
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    return true;
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  }
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  bool canReorderDoubled(vector<int> &arr) {
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    int n = arr.size();
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    vector<int> pos, neg;
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    int zeroes = 0;
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    for (int i : arr) {
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      if (i > 0) {
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        pos.push_back(i);
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      } else if (i < 0) {
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        neg.push_back(i);
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      } else {
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        zeroes++;
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      }
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    }
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    if (zeroes % 2 != 0) {
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      return false;
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    }
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    if (neg.size() % 2 != 0 or pos.size() % 2 != 0) {
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      return false;
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    }
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    for (int i = 0; i < neg.size(); i++) {
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      neg[i] = -1 * neg[i];
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    }
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    sort(pos.begin(), pos.end());
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    sort(neg.begin(), neg.end());
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    return func(pos) and func(neg);
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  }
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};