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class Solution {
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public:
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    vector<int> findErrorNums(vector<int>& nums) 
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    {
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        unordered_map<int,int> m;
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        int p,q;
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        for(auto &x:nums)
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        {
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            m[x]++;
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            if(m[x]==2)
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            {
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                p=x;
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                break;
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            }
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        }
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        int n=nums.size();
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        q=(n*(n+1))/2-accumulate(nums.begin(),nums.end(),0)+p;
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        return {p,q};
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    }
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};
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