Random
Time Limit : 2000/1000ms (Java/Other) Memory Limit : 65536/65536K (Java/Other)
Total Submission(s) : 0 Accepted Submission(s) : 0
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Problem Description
$N$ numbers, randomly generated between $ [0,1] $
Make $M$ operation, $\frac {1} {2} $ probability to delete the maximum value, $ \frac {1} {2} $ probability to delete the minimum value
Calculate the sum of expected value module $10^9+7 $
Make $M$ operation, $\frac {1} {2} $ probability to delete the maximum value, $ \frac {1} {2} $ probability to delete the minimum value
Calculate the sum of expected value module $10^9+7 $
Input
Each test contains multiple test cases. The first line contains the number of test cases $T$($1\le T \le 10000$). Description of the test cases follows.
The first line of each test case contains two integers $n,m$
$1\le m \le n \le 10^9$
The first line of each test case contains two integers $n,m$
$1\le m \le n \le 10^9$
Output
For each test case, print one integer — the answer to the problem.
Sample Input
2 2 2 3 1
Sample Output
0 1
Source
2022“杭电杯”中国大学生算法设计超级联赛（1）