/in/foo.cc: In function 'int read()':
/in/foo.cc:11:5: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
     while(!isdigit(c=gr())); int x=c^48;
     ^~~~~
/in/foo.cc:11:30: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
     while(!isdigit(c=gr())); int x=c^48;
                              ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:74:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         mid = l + r >> 1;
               ~~^~~