# for i in $(seq 1 5); do time ./int_sort_18.o; done
       19.55 real        19.04 user         0.29 sys
       19.54 real        19.04 user         0.29 sys
       19.56 real        19.06 user         0.29 sys
       19.57 real        19.04 user         0.31 sys
       19.57 real        19.06 user         0.30 sys