/in/foo.cc: In function 'void read(int&)':
/in/foo.cc:9:4: 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:9:34: 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
                                  ^