tower.cpp: In function 'std::string guess(int, int)':
tower.cpp:16:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
16 | #define forr(i,x,y) for(int i = x;i<=y;i++)
......
43 | forr(i , 0 , sz(let) - 1)
| ~~~~~~~~~~~~~~~~~~~
tower.cpp:43:5: note: in expansion of macro 'forr'
43 | forr(i , 0 , sz(let) - 1)
| ^~~~
tower.cpp:16:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
16 | #define forr(i,x,y) for(int i = x;i<=y;i++)
......
47 | forr(j , i + 1 , sz(let) - 1)
| ~~~~~~~~~~~~~~~~~~~~~~~
tower.cpp:47:9: note: in expansion of macro 'forr'
47 | forr(j , i + 1 , sz(let) - 1)
| ^~~~
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
/usr/bin/ld: /tmp/ccbYV01y.o: in function `guess[abi:cxx11](int, int)':
tower.cpp:(.text+0x270): undefined reference to `query(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
/usr/bin/ld: tower.cpp:(.text+0x386): undefined reference to `query(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
collect2: error: ld returned 1 exit status