books.cpp:37:20: error: empty character constant
37 | return ''
| ^~
books.cpp: In function 'void solve(int, int, ll, int)':
books.cpp:33:25: error: 'mid' was not declared in this scope
33 | if(p && sum + a[mid] <= 2 * A) {
| ^~~
books.cpp:34:37: error: could not convert '{mid}' from '<brace-enclosed initializer list>' to 'std::vector<int>'
34 | vector<int> ans = { mid };
| ^
| |
| <brace-enclosed initializer list>
books.cpp:37:20: error: return-statement with a value, in function returning 'void' [-fpermissive]
37 | return ''
| ^~
books.cpp:37:22: error: expected ';' before '}' token
37 | return ''
| ^
| ;
38 | }
| ~