BEGIN{ lowerlimit=-8 upperlimit=7 BIN[0]="0000" BIN[1]="0001" BIN[2]="0010" BIN[3]="0011" BIN[4]="0100" BIN[5]="0101" BIN[6]="0110" BIN[7]="0111" BIN[-8]="1000" BIN[-7]="1001" BIN[-6]="1010" BIN[-5]="1011" BIN[-4]="1100" BIN[-3]="1101" BIN[-2]="1110" BIN[-1]="1111" BIN[8]="1000" BIN[9]="1001" BIN[10]="1010" BIN[11]="1011" BIN[12]="1100" BIN[13]="1101" BIN[14]="1110" BIN[15]="1111" BIN[-16]="0000" BIN[-15]="0001" BIN[-14]="0010" BIN[-13]="0011" BIN[-12]="0100" BIN[-11]="0101" BIN[-10]="0110" BIN[-9]="0111" for (i=lowerlimit;i<=upperlimit;i++) { for (j=lowerlimit;j<=upperlimit;j++) { d=i+j a=BIN[i] ; if (a=="") a="----" b=BIN[j] ; if (b=="") b="----" c=BIN[d] ; if (c=="") c="----" f=(d<lowerlimit || d>upperlimit)?"x":"o"; } } }
Standard input is empty
-8 (1000) + -8 (1000) = -16 (0000) x -8 (1000) + -7 (1001) = -15 (0001) x -8 (1000) + -6 (1010) = -14 (0010) x -8 (1000) + -5 (1011) = -13 (0011) x -8 (1000) + -4 (1100) = -12 (0100) x -8 (1000) + -3 (1101) = -11 (0101) x -8 (1000) + -2 (1110) = -10 (0110) x -8 (1000) + -1 (1111) = -9 (0111) x -8 (1000) + +0 (0000) = -8 (1000) o -8 (1000) + +1 (0001) = -7 (1001) o -8 (1000) + +2 (0010) = -6 (1010) o -8 (1000) + +3 (0011) = -5 (1011) o -8 (1000) + +4 (0100) = -4 (1100) o -8 (1000) + +5 (0101) = -3 (1101) o -8 (1000) + +6 (0110) = -2 (1110) o -8 (1000) + +7 (0111) = -1 (1111) o -7 (1001) + -8 (1000) = -15 (0001) x -7 (1001) + -7 (1001) = -14 (0010) x -7 (1001) + -6 (1010) = -13 (0011) x -7 (1001) + -5 (1011) = -12 (0100) x -7 (1001) + -4 (1100) = -11 (0101) x -7 (1001) + -3 (1101) = -10 (0110) x -7 (1001) + -2 (1110) = -9 (0111) x -7 (1001) + -1 (1111) = -8 (1000) o -7 (1001) + +0 (0000) = -7 (1001) o -7 (1001) + +1 (0001) = -6 (1010) o -7 (1001) + +2 (0010) = -5 (1011) o -7 (1001) + +3 (0011) = -4 (1100) o -7 (1001) + +4 (0100) = -3 (1101) o -7 (1001) + +5 (0101) = -2 (1110) o -7 (1001) + +6 (0110) = -1 (1111) o -7 (1001) + +7 (0111) = +0 (0000) o -6 (1010) + -8 (1000) = -14 (0010) x -6 (1010) + -7 (1001) = -13 (0011) x -6 (1010) + -6 (1010) = -12 (0100) x -6 (1010) + -5 (1011) = -11 (0101) x -6 (1010) + -4 (1100) = -10 (0110) x -6 (1010) + -3 (1101) = -9 (0111) x -6 (1010) + -2 (1110) = -8 (1000) o -6 (1010) + -1 (1111) = -7 (1001) o -6 (1010) + +0 (0000) = -6 (1010) o -6 (1010) + +1 (0001) = -5 (1011) o -6 (1010) + +2 (0010) = -4 (1100) o -6 (1010) + +3 (0011) = -3 (1101) o -6 (1010) + +4 (0100) = -2 (1110) o -6 (1010) + +5 (0101) = -1 (1111) o -6 (1010) + +6 (0110) = +0 (0000) o -6 (1010) + +7 (0111) = +1 (0001) o -5 (1011) + -8 (1000) = -13 (0011) x -5 (1011) + -7 (1001) = -12 (0100) x -5 (1011) + -6 (1010) = -11 (0101) x -5 (1011) + -5 (1011) = -10 (0110) x -5 (1011) + -4 (1100) = -9 (0111) x -5 (1011) + -3 (1101) = -8 (1000) o -5 (1011) + -2 (1110) = -7 (1001) o -5 (1011) + -1 (1111) = -6 (1010) o -5 (1011) + +0 (0000) = -5 (1011) o -5 (1011) + +1 (0001) = -4 (1100) o -5 (1011) + +2 (0010) = -3 (1101) o -5 (1011) + +3 (0011) = -2 (1110) o -5 (1011) + +4 (0100) = -1 (1111) o -5 (1011) + +5 (0101) = +0 (0000) o -5 (1011) + +6 (0110) = +1 (0001) o -5 (1011) + +7 (0111) = +2 (0010) o -4 (1100) + -8 (1000) = -12 (0100) x -4 (1100) + -7 (1001) = -11 (0101) x -4 (1100) + -6 (1010) = -10 (0110) x -4 (1100) + -5 (1011) = -9 (0111) x -4 (1100) + -4 (1100) = -8 (1000) o -4 (1100) + -3 (1101) = -7 (1001) o -4 (1100) + -2 (1110) = -6 (1010) o -4 (1100) + -1 (1111) = -5 (1011) o -4 (1100) + +0 (0000) = -4 (1100) o -4 (1100) + +1 (0001) = -3 (1101) o -4 (1100) + +2 (0010) = -2 (1110) o -4 (1100) + +3 (0011) = -1 (1111) o -4 (1100) + +4 (0100) = +0 (0000) o -4 (1100) + +5 (0101) = +1 (0001) o -4 (1100) + +6 (0110) = +2 (0010) o -4 (1100) + +7 (0111) = +3 (0011) o -3 (1101) + -8 (1000) = -11 (0101) x -3 (1101) + -7 (1001) = -10 (0110) x -3 (1101) + -6 (1010) = -9 (0111) x -3 (1101) + -5 (1011) = -8 (1000) o -3 (1101) + -4 (1100) = -7 (1001) o -3 (1101) + -3 (1101) = -6 (1010) o -3 (1101) + -2 (1110) = -5 (1011) o -3 (1101) + -1 (1111) = -4 (1100) o -3 (1101) + +0 (0000) = -3 (1101) o -3 (1101) + +1 (0001) = -2 (1110) o -3 (1101) + +2 (0010) = -1 (1111) o -3 (1101) + +3 (0011) = +0 (0000) o -3 (1101) + +4 (0100) = +1 (0001) o -3 (1101) + +5 (0101) = +2 (0010) o -3 (1101) + +6 (0110) = +3 (0011) o -3 (1101) + +7 (0111) = +4 (0100) o -2 (1110) + -8 (1000) = -10 (0110) x -2 (1110) + -7 (1001) = -9 (0111) x -2 (1110) + -6 (1010) = -8 (1000) o -2 (1110) + -5 (1011) = -7 (1001) o -2 (1110) + -4 (1100) = -6 (1010) o -2 (1110) + -3 (1101) = -5 (1011) o -2 (1110) + -2 (1110) = -4 (1100) o -2 (1110) + -1 (1111) = -3 (1101) o -2 (1110) + +0 (0000) = -2 (1110) o -2 (1110) + +1 (0001) = -1 (1111) o -2 (1110) + +2 (0010) = +0 (0000) o -2 (1110) + +3 (0011) = +1 (0001) o -2 (1110) + +4 (0100) = +2 (0010) o -2 (1110) + +5 (0101) = +3 (0011) o -2 (1110) + +6 (0110) = +4 (0100) o -2 (1110) + +7 (0111) = +5 (0101) o -1 (1111) + -8 (1000) = -9 (0111) x -1 (1111) + -7 (1001) = -8 (1000) o -1 (1111) + -6 (1010) = -7 (1001) o -1 (1111) + -5 (1011) = -6 (1010) o -1 (1111) + -4 (1100) = -5 (1011) o -1 (1111) + -3 (1101) = -4 (1100) o -1 (1111) + -2 (1110) = -3 (1101) o -1 (1111) + -1 (1111) = -2 (1110) o -1 (1111) + +0 (0000) = -1 (1111) o -1 (1111) + +1 (0001) = +0 (0000) o -1 (1111) + +2 (0010) = +1 (0001) o -1 (1111) + +3 (0011) = +2 (0010) o -1 (1111) + +4 (0100) = +3 (0011) o -1 (1111) + +5 (0101) = +4 (0100) o -1 (1111) + +6 (0110) = +5 (0101) o -1 (1111) + +7 (0111) = +6 (0110) o +0 (0000) + -8 (1000) = -8 (1000) o +0 (0000) + -7 (1001) = -7 (1001) o +0 (0000) + -6 (1010) = -6 (1010) o +0 (0000) + -5 (1011) = -5 (1011) o +0 (0000) + -4 (1100) = -4 (1100) o +0 (0000) + -3 (1101) = -3 (1101) o +0 (0000) + -2 (1110) = -2 (1110) o +0 (0000) + -1 (1111) = -1 (1111) o +0 (0000) + +0 (0000) = +0 (0000) o +0 (0000) + +1 (0001) = +1 (0001) o +0 (0000) + +2 (0010) = +2 (0010) o +0 (0000) + +3 (0011) = +3 (0011) o +0 (0000) + +4 (0100) = +4 (0100) o +0 (0000) + +5 (0101) = +5 (0101) o +0 (0000) + +6 (0110) = +6 (0110) o +0 (0000) + +7 (0111) = +7 (0111) o +1 (0001) + -8 (1000) = -7 (1001) o +1 (0001) + -7 (1001) = -6 (1010) o +1 (0001) + -6 (1010) = -5 (1011) o +1 (0001) + -5 (1011) = -4 (1100) o +1 (0001) + -4 (1100) = -3 (1101) o +1 (0001) + -3 (1101) = -2 (1110) o +1 (0001) + -2 (1110) = -1 (1111) o +1 (0001) + -1 (1111) = +0 (0000) o +1 (0001) + +0 (0000) = +1 (0001) o +1 (0001) + +1 (0001) = +2 (0010) o +1 (0001) + +2 (0010) = +3 (0011) o +1 (0001) + +3 (0011) = +4 (0100) o +1 (0001) + +4 (0100) = +5 (0101) o +1 (0001) + +5 (0101) = +6 (0110) o +1 (0001) + +6 (0110) = +7 (0111) o +1 (0001) + +7 (0111) = +8 (1000) x +2 (0010) + -8 (1000) = -6 (1010) o +2 (0010) + -7 (1001) = -5 (1011) o +2 (0010) + -6 (1010) = -4 (1100) o +2 (0010) + -5 (1011) = -3 (1101) o +2 (0010) + -4 (1100) = -2 (1110) o +2 (0010) + -3 (1101) = -1 (1111) o +2 (0010) + -2 (1110) = +0 (0000) o +2 (0010) + -1 (1111) = +1 (0001) o +2 (0010) + +0 (0000) = +2 (0010) o +2 (0010) + +1 (0001) = +3 (0011) o +2 (0010) + +2 (0010) = +4 (0100) o +2 (0010) + +3 (0011) = +5 (0101) o +2 (0010) + +4 (0100) = +6 (0110) o +2 (0010) + +5 (0101) = +7 (0111) o +2 (0010) + +6 (0110) = +8 (1000) x +2 (0010) + +7 (0111) = +9 (1001) x +3 (0011) + -8 (1000) = -5 (1011) o +3 (0011) + -7 (1001) = -4 (1100) o +3 (0011) + -6 (1010) = -3 (1101) o +3 (0011) + -5 (1011) = -2 (1110) o +3 (0011) + -4 (1100) = -1 (1111) o +3 (0011) + -3 (1101) = +0 (0000) o +3 (0011) + -2 (1110) = +1 (0001) o +3 (0011) + -1 (1111) = +2 (0010) o +3 (0011) + +0 (0000) = +3 (0011) o +3 (0011) + +1 (0001) = +4 (0100) o +3 (0011) + +2 (0010) = +5 (0101) o +3 (0011) + +3 (0011) = +6 (0110) o +3 (0011) + +4 (0100) = +7 (0111) o +3 (0011) + +5 (0101) = +8 (1000) x +3 (0011) + +6 (0110) = +9 (1001) x +3 (0011) + +7 (0111) = +10 (1010) x +4 (0100) + -8 (1000) = -4 (1100) o +4 (0100) + -7 (1001) = -3 (1101) o +4 (0100) + -6 (1010) = -2 (1110) o +4 (0100) + -5 (1011) = -1 (1111) o +4 (0100) + -4 (1100) = +0 (0000) o +4 (0100) + -3 (1101) = +1 (0001) o +4 (0100) + -2 (1110) = +2 (0010) o +4 (0100) + -1 (1111) = +3 (0011) o +4 (0100) + +0 (0000) = +4 (0100) o +4 (0100) + +1 (0001) = +5 (0101) o +4 (0100) + +2 (0010) = +6 (0110) o +4 (0100) + +3 (0011) = +7 (0111) o +4 (0100) + +4 (0100) = +8 (1000) x +4 (0100) + +5 (0101) = +9 (1001) x +4 (0100) + +6 (0110) = +10 (1010) x +4 (0100) + +7 (0111) = +11 (1011) x +5 (0101) + -8 (1000) = -3 (1101) o +5 (0101) + -7 (1001) = -2 (1110) o +5 (0101) + -6 (1010) = -1 (1111) o +5 (0101) + -5 (1011) = +0 (0000) o +5 (0101) + -4 (1100) = +1 (0001) o +5 (0101) + -3 (1101) = +2 (0010) o +5 (0101) + -2 (1110) = +3 (0011) o +5 (0101) + -1 (1111) = +4 (0100) o +5 (0101) + +0 (0000) = +5 (0101) o +5 (0101) + +1 (0001) = +6 (0110) o +5 (0101) + +2 (0010) = +7 (0111) o +5 (0101) + +3 (0011) = +8 (1000) x +5 (0101) + +4 (0100) = +9 (1001) x +5 (0101) + +5 (0101) = +10 (1010) x +5 (0101) + +6 (0110) = +11 (1011) x +5 (0101) + +7 (0111) = +12 (1100) x +6 (0110) + -8 (1000) = -2 (1110) o +6 (0110) + -7 (1001) = -1 (1111) o +6 (0110) + -6 (1010) = +0 (0000) o +6 (0110) + -5 (1011) = +1 (0001) o +6 (0110) + -4 (1100) = +2 (0010) o +6 (0110) + -3 (1101) = +3 (0011) o +6 (0110) + -2 (1110) = +4 (0100) o +6 (0110) + -1 (1111) = +5 (0101) o +6 (0110) + +0 (0000) = +6 (0110) o +6 (0110) + +1 (0001) = +7 (0111) o +6 (0110) + +2 (0010) = +8 (1000) x +6 (0110) + +3 (0011) = +9 (1001) x +6 (0110) + +4 (0100) = +10 (1010) x +6 (0110) + +5 (0101) = +11 (1011) x +6 (0110) + +6 (0110) = +12 (1100) x +6 (0110) + +7 (0111) = +13 (1101) x +7 (0111) + -8 (1000) = -1 (1111) o +7 (0111) + -7 (1001) = +0 (0000) o +7 (0111) + -6 (1010) = +1 (0001) o +7 (0111) + -5 (1011) = +2 (0010) o +7 (0111) + -4 (1100) = +3 (0011) o +7 (0111) + -3 (1101) = +4 (0100) o +7 (0111) + -2 (1110) = +5 (0101) o +7 (0111) + -1 (1111) = +6 (0110) o +7 (0111) + +0 (0000) = +7 (0111) o +7 (0111) + +1 (0001) = +8 (1000) x +7 (0111) + +2 (0010) = +9 (1001) x +7 (0111) + +3 (0011) = +10 (1010) x +7 (0111) + +4 (0100) = +11 (1011) x +7 (0111) + +5 (0101) = +12 (1100) x +7 (0111) + +6 (0110) = +13 (1101) x +7 (0111) + +7 (0111) = +14 (1110) x