/in/p1.cpp: In function 'void display(int, std::__cxx11::string, std::__cxx11::string, int*, int)':
/in/p1.cpp:69:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (j = 0; j < myword.length(); j++)
              ~~^~~~~~~~~~~~~~~~~
/in/p1.cpp:92:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (j = 0; j < used_letter.length(); j++)
              ~~^~~~~~~~~~~~~~~~~~~~~~
/in/p1.cpp:66:6: warning: unused variable 'ii' [-Wunused-variable]
  int ii = 0;
      ^~
/in/p1.cpp: In function 'int main()':
/in/p1.cpp:150:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (i = 0; i < input_history.length(); i++)
               ~~^~~~~~~~~~~~~~~~~~~~~~~~
/in/p1.cpp:172:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (i = 0; i < right_history.length(); i++)
               ~~^~~~~~~~~~~~~~~~~~~~~~~~
/in/p1.cpp:187:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while ((begin = myword.find(input_letter, begin)) != string::npos)     //*****find all the same letter in the correspoding word and obtain the position of the letter
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~
/in/p1.cpp:109:6: warning: unused variable 'arrsize' [-Wunused-variable]
  int arrsize;
      ^~~~~~~