Largest Continuous Sequence Zero Sum

• Time : $O(n)$
• Space : $O(n)$

vector<int> Solution::lszero(vector<int> &A) {
    unordered_map<int,int> mp;
    mp[0] = -1;
    int start = -1, len = -1;
    for(int i = 0, sum = 0; i < A.size(); i++) {
        sum += A[i];
        if(!mp.count(sum)) mp[sum] = i;
        else {
            int l = i - mp[sum];
            if(len < l) {
                start = mp[sum];
                len = l;
            }
        }
    }
    vector<int> res;
    for(int i = start + 1; i <= start + len; i++) res.push_back(A[i]);
    return res;
}