Main.cc:23:30: error: ISO C++ forbids declaration of ‘operator<’ with no type [-fpermissive]
operator < (const node & b) const
^~~~~
Main.cc: In function ‘int main()’:
Main.cc:58:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &q);
~~~~~^~~~~~~~~~~~~~~~~
Main.cc:62:11: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &w);
~~~~~^~~~~~~~~~
Main.cc:70:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &x, &y);
~~~~~^~~~~~~~~~~~~~~~~