/in/foo.cc: In function 'int main()':
/in/foo.cc:53:9: warning: unused variable 'tx' [-Wunused-variable]
     int tx = idx[x[i]], ty = y[i], t = L[x[i]];
         ^~
/in/foo.cc:53:25: warning: unused variable 'ty' [-Wunused-variable]
     int tx = idx[x[i]], ty = y[i], t = L[x[i]];
                         ^~