/in/foo.cc: In function 'int turn(char*, int*)':
/in/foo.cc:19:4: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
    while(isdigit(s[++i])) x=x*10+s[i]-'0';--i;
    ^~~~~
/in/foo.cc:19:43: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
    while(isdigit(s[++i])) x=x*10+s[i]-'0';--i;
                                           ^~
/in/foo.cc:28:50: warning: array subscript has type 'char' [-Wchar-subscripts]
    while(!stk2.empty()&&pre[stk2.top()]>=pre[s[i]]) stk1.push(stk2.top()),stk2.pop();
                                                  ^
/in/foo.cc:34:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i=0;i*2<cur;i++) swap(t[i],t[cur-i-1]);t[cur]='\0';
  ^~~
/in/foo.cc:34:49: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  for(int i=0;i*2<cur;i++) swap(t[i],t[cur-i-1]);t[cur]='\0';
                                                 ^
/in/foo.cc: In function 'int operater(int, int, int)':
/in/foo.cc:38:6: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int ans;
      ^~~