1-3+2-6+3-9+4-12+...+31-93+32-96+33-99=17x33-3(1+2+3+...+31+32+33)=-2*17*33
把旁仔清式戚差子变成运前
1+2+3+...+31+32+33-3-6-9-12-15-...-99
=1+2+3+...+31+32+33-3x(1+2+3+...+31+32+33)
=-2x17x33
=-1122
1-3+2-6+3-9+4-12+...+31-93+32-96+33-99
=(1+2+3+...+33)-(3+6+9+...+99)
=(1+2+3+...+33)-3(1+2+3+...+33)
=17×33-3×17×33
=(1-3)×17×33
=-2×17×33
=-1122