# 【Ural 1057】Amount of Degrees / 题解

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### Statement

Create a code to determine the amount of integers, lying in the set [X;Y] and being a sum of exactly K different integer degrees of B.
Example. Let X=15, Y=20, K=2, B=2. By this example 3 numbers are the sum of exactly two integer degrees of number 2:
$17 = 2^4+2^0$,
$18 = 2^4+2^1$,
$20 = 2^4+2^2$.

#### Input

The first line of input contains integers X and Y, separated with a space $(1 ≤ X ≤ Y ≤ 2^{31}−1)$. The next two lines contain integers K and B $(1 ≤ K ≤ 20; 2 ≤ B ≤ 10)$.

#### Output

Output should contain a single integer — the amount of integers, lying between X and Y, being a sum of exactly K different integer degrees of B.

### 代码

1. oyyj603470138
Sep 24, 2018

两位大佬。。