最接近零的子数组和

给定一个整数数组，找到一个和最接近于零的子数组。返回第一个和最有一个指数。你的代码应该返回满足要求的子数组的起始位置和结束位置

    struct Node {
        int end;
        int val;
        Node(int e, int v) : end(e), val(v) {}
    };
    static bool cmp(const Node& a, const Node& b) {
        return a.val < b.val; 
    }

class Solution {
public:
    vector<int> subarraySumClosest(const vector<int>& nums){

        vector<Node> vec;
        if (nums.empty()) {
            return {};
        }
        int sum = 0; 
        for (int i = 0; i < nums.size(); ++i) {
            sum += nums[i];
            vec.push_back(Node(i, sum));
        }

        sort(vec.begin(), vec.end(), cmp);

// key point
        int min_dif = INT_MAX; 
        for (int i = 0; i < vec.size(); ++i) {
            min_dif = min(abs(vec.front().val), min_dif);
            if (i) {
                min_dif = min(min_dif, abs(vec[i].val - vec[i - 1].val));
            }
        }

vector<int> res;

for (int i = 0; i < vec.size(); ++i) {
    if (abs(vec[i].val) == min_dif) {
        res.push_back(0);
        res.push_back(vec[i].end);
        break;
    }
    if (i && abs(vec[i].val - vec[i - 1].val) == min_dif) {
        if (vec[i].end < vec[i - 1].end) {
            res.push_back(vec[i].end + 1);
            res.push_back(vec[i - 1].end);
        }
        else {
            res.push_back(vec[i - 1].end + 1);
            res.push_back(vec[i].end);
        }
        break;
    }
}
cout << min_dif << endl;
return res; 
    }
};