Codeforces Round 716 (Div. 2)
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Baby Badawy's first words were "AND 0 SUM BIG", so he decided to solve the following problem. Given two integers $n$ and $k$, count the number of arrays of length $n$ such that:
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- all its elements are integers between
$0$and$2^k-1$(inclusive); - the bitwise AND of all its elements is
$0$; - the sum of its elements is as large as possible.
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Since the answer can be very large, print its remainder when divided by $10^9+7$.
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Input
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The first line contains an integer $t$ ($1 \le t \le 10$) — the number of test cases you need to solve.
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Each test case consists of a line containing two integers $n$ and $k$ ($1 \le n \le 10^{5}$, $1 \le k \le 20$).
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Output
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For each test case, print the number of arrays satisfying the conditions. Since the answer can be very large, print its remainder when divided by $10^9+7$.
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Note
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In the first example, the $4$ arrays are:
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$[3,0]$,$[0,3]$,$[1,2]$,$[2,1]$.
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样例
Input #1
2
2 2
100000 20
Output #1
4
226732710
InputCopy
OutputCopy
题目信息
标签
位运算
组合数学
数学
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