Compilare: main.cpp: In function 'ii merge(int, int)': main.cpp:21:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= s[p].size(); ++i) { ~~^~~~~~~~~~~~~~ main.cpp:27:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (query(cpy.insert(i, s[q], res, mid)) == s[p].size()+mid) lo = mid; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:44:8: warning: array subscript has type 'char' [-Wchar-subscripts] cnt[i] = query(string(N, ch)); ^ main.cpp:45:6: warning: array subscript has type 'char' [-Wchar-subscripts] s[i] = string(cnt[i], ch); ^ main.cpp:45:22: warning: array subscript has type 'char' [-Wchar-subscripts] s[i] = string(cnt[i], ch); ^