Minimum Operations to Make the Array Alternating LeetCode solution in C++

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class Solution {
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 public:
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  int minimumOperations(vector<int> &nums) {
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    int totalEven = 0, totalOdd = 0;
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    unordered_map<int, int> mapEven, mapOdd;
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    for (int i = 0; i < nums.size(); i++) {
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      if (i % 2 == 0) {
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        totalEven++;
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        mapEven[nums[i]]++;
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      }
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      else {
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        totalOdd++;
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        mapOdd[nums[i]]++;
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      }
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    }
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    int firstEvenCount = 0, firstEven = 0;
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    int secondEvenCount = 0, secondEven = 0;
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    for (auto it = mapEven.begin(); it != mapEven.end(); it++) {
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      int num = it->first;
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      int count = it->second;
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      if (count >= firstEvenCount) {
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        secondEvenCount = firstEvenCount;
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        secondEven = firstEven;
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        firstEvenCount = count;
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        firstEven = num;
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      }
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      else if (count >= secondEvenCount) {
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        secondEvenCount = count;
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        secondEven = num;
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      }
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    }
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    int firstOddCount = 0, firstOdd = 0;
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    int secondOddCount = 0, secondOdd = 0;
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    for (auto it = mapOdd.begin(); it != mapOdd.end(); it++) {
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      int num = it->first;
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      int count = it->second;
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      if (count >= firstOddCount) {
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        secondOddCount = firstOddCount;
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        secondOdd = firstOdd;
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        firstOddCount = count;
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        firstOdd = num;
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      }
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      else if (count >= secondOddCount) {
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        secondOddCount = count;
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        secondOdd = num;
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      }
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    }
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    int operationsEven = 0, operationsOdd = 0;
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    operationsEven = totalEven - firstEvenCount;
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    if (firstEven != firstOdd)
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      operationsEven += (totalOdd - firstOddCount);
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    else
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      operationsEven += (totalOdd - secondOddCount);
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    operationsOdd = totalOdd - firstOddCount;
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    if (firstOdd != firstEven)
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      operationsOdd += (totalEven - firstEvenCount);
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    else
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      operationsOdd += (totalEven - secondEvenCount);
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    return min(operationsEven, operationsOdd);
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  }
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};