Description

Submission

class Solution {
    bool samePrefix(string s1, string s2) {
        if(s2.length() > s1.length()) swap(s1, s2);
        return s1.substr(0, s2.length()) == s2;
    }
public:
    vector<string> removeSubfolders(vector<string>& folder) {
        int n = folder.size();
        vector<int> remain(n, 1);
        vector<string> rets;
        
        for(auto& f: folder) {
            f.push_back('/');
        }
        
        sort(folder.begin(), folder.end());
        
        for(int i = 0; i < n; ++i) {
            auto& s1 = folder[i];
            int j = i + 1;
            for(; j < n; ++j) {
                auto& s2 = folder[j];
                
                if(samePrefix(s1, s2)) remain[j] = 0; 
                else {
                    i = j - 1;
                    break;
                }
            }
        }

        for(int i = 0; i < n; ++i) {
            if(remain[i]) {
                folder[i].pop_back();
                rets.push_back(folder[i]);
            }
        }
        
        return rets;
    }
};