When x = 1, f(x) = 14.

When 7/8 ≤ x

7/4≤2x & lt； 2，7/2≤x & lt； 4.7≤8x & lt； eight

f(x)= 1+3+7 = 1 1

When 3/4 ≤ x

3/2≤2x & lt； 7/4，3≤x & lt； 7/2，6≤8x & lt； seven

f(x) = 1 + 3 + 6 = 10

A similar discussion is as follows

When 5/8 ≤ x

When 1/2 ≤ x

When 3/8 ≤ x

When 1/4 ≤ x

When 1/8 ≤ x

When 0 ≤ x