Compilare: main.cpp: In function 'std::string add(std::string&, std::string&)': main.cpp:30:22: warning: comparison of integer expressions of different signedness: 'int' and 'const long unsigned int' [-Wsign-compare] 30 | for (int i = 0; i < max(a.size(), b.size()); ++i) | ~~^~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:32:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | int A = (i < a.size() ? a[i]-'0' : 0); | ~~^~~~~~~~~~ main.cpp:33:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | int B = (i < b.size() ? b[i]-'0' : 0); | ~~^~~~~~~~~~ In file included from /usr/include/c++/12.2.1/ios:40, from /usr/include/c++/12.2.1/istream:38, from /usr/include/c++/12.2.1/sstream:38, from /usr/include/c++/12.2.1/complex:45, from /usr/include/c++/12.2.1/ccomplex:39, from /usr/include/c++/12.2.1/x86_64-pc-linux-gnu/bits/stdc++.h:54, from main.cpp:6: In static member function 'static constexpr std::char_traits<char>::char_type* std::char_traits<char>::copy(char_type*, const char_type*, std::size_t)', inlined from 'static constexpr void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_S_copy(_CharT*, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /usr/include/c++/12.2.1/bits/basic_string.h:423:21, inlined from 'static constexpr void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_S_copy(_CharT*, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /usr/include/c++/12.2.1/bits/basic_string.h:418:7, inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_replace(size_type, size_type, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /usr/include/c++/12.2.1/bits/basic_string.tcc:532:22, inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::assign(const _CharT*) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /usr/include/c++/12.2.1/bits/basic_string.h:1647:19, inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::operator=(const _CharT*) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /usr/include/c++/12.2.1/bits/basic_string.h:815:28, inlined from 'int main()' at main.cpp:47:15: /usr/include/c++/12.2.1/bits/char_traits.h:431:56: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' accessing 9223372036854775810 or more bytes at offsets -4611686018427387902 and [-4611686018427387903, 4611686018427387904] may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict] 431 | return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n)); | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~