leetcode 985. sum of even numbers after queries

class  {
public:
    vector<int> sumEvenAfterQueries(vector<int>& A, vector<vector<int>>& queries) {
        int n = A.size();
        int sum = 0;
        for (int i = 0; i < n; i++)
            if (A[i] % 2 == 0)
                sum += A[i];
        vector<int> ans;
        for (int i = 0; i < queries.size(); i++) {
            int x = queries[i][0], k = queries[i][1];
            if (A[k] % 2 == 0) {
                if (x % 2 == 0) sum += x;
                else sum -= A[k];
            }
            else {
                if (x % 2 != 0) sum += A[k] + x;
            }
            A[k] += x;
            ans.push_back(sum);
        }
        return ans;
    }
};