Compilare: user.cpp: In function ‘int main()’: user.cpp:62:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] cnt[str[i]]++; ^ user.cpp:68:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[ch1][ch2]++; ^ user.cpp:68:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[ch1][ch2]++; ^ user.cpp:73:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] add_Edge(1, i, fr[ch1][ch2]); ^ user.cpp:73:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] add_Edge(1, i, fr[ch1][ch2]); ^ user.cpp:108:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] sol[ch1].push_back(v[i - 2].back()); ^ user.cpp:110:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] sol[ch2].push_back(v[i - 2].back()); ^ user.cpp:123:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] fprintf(fout,"%d " ,sol[str[i]].back()); ^ user.cpp:124:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] sol[str[i]].pop_back(); ^ user.cpp:54:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, n, m; ^ user.cpp:55:20: warning: unused variable ‘ch’ [-Wunused-variable] char ch1, ch2, ch; ^ user.cpp:58:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&m); ^ user.cpp:59:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%s " ,str + 1); ^ user.cpp:65:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%c %c " ,&ch1,&ch2); ^