/in/foo.cc:62:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){register int i,n,len; register ll want,cur;  m['^']=4; m['*']=m['/']=3; m['+']=m['-']=2; m['(']=m[')']=1;
      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:65:18: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'll* {aka long long int*}' [-Wformat=]
     scanf("%d",&n);getchar();
                  ^