Compilare: main.cpp: In function 'int to_int(const std::string&)': main.cpp:7:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 7 | for(int i = 0;i < s.size();++i) | ~~^~~~~~~~~~ In file included from /usr/include/c++/12.2.1/bits/stl_iterator.h:85, from /usr/include/c++/12.2.1/bits/stl_algobase.h:67, from /usr/include/c++/12.2.1/bits/specfun.h:45, from /usr/include/c++/12.2.1/cmath:1935, from /usr/include/c++/12.2.1/x86_64-pc-linux-gnu/bits/stdc++.h:41, from main.cpp:1: In function 'constexpr decltype (::new(void*(0)) _Tp) std::construct_at(_Tp*, _Args&& ...) [with _Tp = pair<int, int>; _Args = {pair<int, int>}]', inlined from 'static constexpr void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = std::pair<int, int>; _Args = {std::pair<int, int>}; _Tp = std::pair<int, int>]' at /usr/include/c++/12.2.1/bits/alloc_traits.h:518:21, inlined from 'constexpr void std::vector<_Tp, _Alloc>::_M_realloc_insert(iterator, _Args&& ...) [with _Args = {std::pair<int, int>}; _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >]' at /usr/include/c++/12.2.1/bits/vector.tcc:462:28, inlined from 'constexpr std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {std::pair<int, int>}; _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >]' at /usr/include/c++/12.2.1/bits/vector.tcc:123:21, inlined from 'constexpr void std::vector<_Tp, _Alloc>::push_back(value_type&&) [with _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >]' at /usr/include/c++/12.2.1/bits/stl_vector.h:1294:21, inlined from 'std::vector<std::pair<int, int> > solve(std::vector<std::vector<int> >&)' at main.cpp:34:15: /usr/include/c++/12.2.1/bits/stl_construct.h:97:73: warning: 'x' may be used uninitialized [-Wmaybe-uninitialized] 97 | { return ::new((void*)__location) _Tp(std::forward<_Args>(__args)...); } | ^ main.cpp: In function 'std::vector<std::pair<int, int> > solve(std::vector<std::vector<int> >&)': main.cpp:26:13: note: 'x' was declared here 26 | int x, y; | ^ In function 'constexpr decltype (::new(void*(0)) _Tp) std::construct_at(_Tp*, _Args&& ...) [with _Tp = pair<int, int>; _Args = {pair<int, int>}]', inlined from 'static constexpr void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = std::pair<int, int>; _Args = {std::pair<int, int>}; _Tp = std::pair<int, int>]' at /usr/include/c++/12.2.1/bits/alloc_traits.h:518:21, inlined from 'constexpr void std::vector<_Tp, _Alloc>::_M_realloc_insert(iterator, _Args&& ...) [with _Args = {std::pair<int, int>}; _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >]' at /usr/include/c++/12.2.1/bits/vector.tcc:462:28, inlined from 'constexpr std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {std::pair<int, int>}; _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >]' at /usr/include/c++/12.2.1/bits/vector.tcc:123:21, inlined from 'constexpr void std::vector<_Tp, _Alloc>::push_back(value_type&&) [with _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >]' at /usr/include/c++/12.2.1/bits/stl_vector.h:1294:21, inlined from 'std::vector<std::pair<int, int> > solve(std::vector<std::vector<int> >&)' at main.cpp:34:15: /usr/include/c++/12.2.1/bits/stl_construct.h:97:73: warning: 'y' may be used uninitialized [-Wmaybe-uninitialized] 97 | { return ::new((void*)__location) _Tp(std::forward<_Args>(__args)...); } | ^ main.cpp: In function 'std::vector<std::pair<int, int> > solve(std::vector<std::vector<int> >&)': main.cpp:26:16: note: 'y' was declared here 26 | int x, y; | ^