/in/foo.cc: In function 'bool ok(int)':
/in/foo.cc:45:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(!cnt)return 1;sum(1,0);
  ^~
/in/foo.cc:45:19: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(!cnt)return 1;sum(1,0);
                   ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:65:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   int mid=l+r>>1;
           ~^~
/in/foo.cc:69:8: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",ans);
  ~~~~~~^~~~~~~~~~