Following is the code for string builder: /****************************************************************************** Online C++ Compiler. Code, Compile, Run and Debug C++ program online. Write your code in this editor and press "Run" button to compile and execute it. *******************************************************************************/ #include <iostream> #include "bits/stdc++.h" using namespace std; class stringbuilder{ private: vector<string> words; vector<char> complete_string; string concatenate_string() public: void insert_words(string s); string get_string(); }; void stringbuilder::insert_word...