Missing Number LeetCode solution in C++

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class Solution {
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 public:
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  int missingNumber(vector<int> &nums) {
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    int n = nums.size();
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    long sum = n * (n + 1) / 2;
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    long temp = 0;
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    for (int i = 0; i < n; i++) {
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      temp += nums[i];
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    }
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    return sum - temp;
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  }
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};