CF1550D.Excellent Arrays

普及/提高-

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题目描述

Let's call an integer array a1,a2,,ana_1, a_2, \dots, a_n good if aiia_i \neq i for each ii .

Let F(a)F(a) be the number of pairs (i,j)(i, j) ( 1i<jn1 \le i < j \le n ) such that ai+aj=i+ja_i + a_j = i + j .

Let's say that an array a1,a2,,ana_1, a_2, \dots, a_n is excellent if:

  • aa is good;
  • lairl \le a_i \le r for each ii ;
  • F(a)F(a) is the maximum possible among all good arrays of size nn .

Given nn , ll and rr , calculate the number of excellent arrays modulo 109+710^9 + 7 .

输入格式

The first line contains a single integer tt ( 1t10001 \le t \le 1000 ) — the number of test cases.

The first and only line of each test case contains three integers nn , ll , and rr ( 2n21052 \le n \le 2 \cdot 10^5 ; 109l1-10^9 \le l \le 1 ; nr109n \le r \le 10^9 ).

It's guaranteed that the sum of nn doesn't exceed 21052 \cdot 10^5 .

输出格式

For each test case, print the number of excellent arrays modulo 109+710^9 + 7 .

输入输出样例

  • 输入#1

    4
    3 0 3
    4 -3 5
    42 -33 55
    69 -42 146

    输出#1

    4
    10
    143922563
    698570404

说明/提示

In the first test case, it can be proven that the maximum F(a)F(a) among all good arrays aa is equal to 22 . The excellent arrays are:

  1. [2,1,2][2, 1, 2] ;
  2. [0,3,2][0, 3, 2] ;
  3. [2,3,2][2, 3, 2] ;
  4. [3,0,1][3, 0, 1] .
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