/in/foo.cc: In function 'll work()':
/in/foo.cc:35:43: warning: array subscript has type 'char' [-Wchar-subscripts]
    while(sb[i]!='('&&!b.empty()&&opr[sb[i]]>=opr[b.top()]){
                                           ^
/in/foo.cc:34:4: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
    if(j){a.push(tmp);}tmp=j=0;
    ^~