Leetcode-888 Fair Candy Swap(公平的糖果交换)

class Solution
{
    public:
        vector<int> fairCandySwap(vector<int>& A, vector<int>& B)
        {
            vector<int> result;
            int total_A = 0,total_B = 0;
            sort(A.begin(),A.end());
            sort(B.begin(),B.end());
            for(auto d:A)
                total_A += d;
            for(auto d:B)
                total_B += d;

            int diff = abs(total_A-total_B)/2;
            int flag = total_A > total_B ? 1:0;//1 alic 多

            if(flag)
            {
                for(auto d:A)
                {
                    auto ptr = lower_bound(B.begin(),B.end(),d-diff);
                    if(ptr!=B.end() && *ptr==d-diff)
                    {
                        result.emplace_back(d);
                        result.emplace_back(d-diff);
                        return result;
                    }
                }
            }
            else
            {
                for(auto d:B)
                {
                    auto ptr = lower_bound(A.begin(),A.end(),d-diff);
                    if(ptr!=A.end() && *ptr==d-diff)
                    {
                        result.emplace_back(d-diff);
                        result.emplace_back(d);
                        return result;
                    }
                }
            }
            return result;
        }
};