1,2,3,4,5,4,3,2,1用加减乘除得出1999,2000,2001,2002

问题描述:

1,2,3,4,5,4,3,2,1用加减乘除得出1999,2000,2001,2002

t=5*4*4*(3+2)*(3+2)=2000
t-1*1=1999
t+1*1=2001
t+1+1=2002