floppy.cpp: In function 'void read_array(int, const std::vector<int>&)':
floppy.cpp:17:5: error: 'stack' was not declared in this scope
17 | stack<int> st;
| ^~~~~
floppy.cpp:3:1: note: 'std::stack' is defined in header '<stack>'; did you forget to '#include <stack>'?
2 | #include <iostream>
+++ |+#include <stack>
3 | #include <string>
floppy.cpp:17:11: error: expected primary-expression before 'int'
17 | stack<int> st;
| ^~~
floppy.cpp:18:5: error: 'st' was not declared in this scope; did you mean 'std'?
18 | st.push(-1);
| ^~
| std
floppy.cpp:43:25: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
43 | while (s.size() < cnt) s = '0' + s;
| ~~~~~~~~~^~~~~
stub.cpp: In function 'void run2()':
stub.cpp:101:30: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
101 | if (query_answers.size() != M) {
| ~~~~~~~~~~~~~~~~~~~~~^~~~