Problem	mountains
User	ruiqi
Submission Time	2023-02-16 15:26:51
Score	0
Max Time	N/A
Max Memory	N/A

Compile Error

mountains.cpp: In function ‘int query(int)’:
mountains.cpp:18:29: error: ‘fw’ was not declared in this scope
18 | for(; x; x -= x&-x) ret += fw[x];
| ^~