/in/foo.cc: In function 'void read(int&)':
/in/foo.cc:9:2: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
  while(!isdigit(c=getchar())); x=c-48;  //不需要输入优化
  ^~~~~
/in/foo.cc:9:32: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
  while(!isdigit(c=getchar())); x=c-48;  //不需要输入优化
                                ^