Return to Answer

deleted 3 characters in body

edited Apr 25 at 23:13

Tcl, 7471 bytes

proc C L {expr -([lmap a\ b $L {list ++3*$a+([incr i]%4?3*$a+$b$b:3*$a0)}])%10==$b}

proc C L {expr -([lmap a\ b $L {list +([incr i]%4?3*$a+$b:3*$a)}])%10==$b}

proc C L {expr -([lmap a\ b $L {list +3*$a+([incr i]%4?$b:0)}])%10==$b}

answered Apr 25 at 23:06

proc C L {expr -([lmap a\ b $L {list +([incr i]%4?3*$a+$b:3*$a)}])%10==$b}