^ 是乘么?
那么
=2^(-1+2-3+4-5.+100)
=2^[ (-1-3-5-7...-99)+(2+4+6+8...+100)]
=2^[ (-1-99)^50/2+(2+100)^50/2]
=2^[ (-1-99+2+100)^50/2]
=2^2^50/2
=100