Question

有一函数f(n),n为正整数,当n=1时f(n+1)+f(n)=3;当n为偶数时f(n+1)-f(n)=3;当n为奇数时

Answer 1

f(2)+f(1)=3

f(2)-f(1)=-1

==>f(1)=2

==>f(2)=1

f(3)-f(2)=3 ==>f(3)=4

f(4)-f(3)=-1 ==>f(4)=3

f(5)-f(4)=3 ==>f(5)=6

f(6)-f(5)=-1 ==>f(6)=5

f(7)=8

f(8)=7

f(n)=n+1,当n为奇数

n-1,当n为偶数