CF1877C Joyboard
Description
Chaneka, a gamer kid, invented a new gaming controller called joyboard. Interestingly, the joyboard she invented can only be used to play one game.
The joyboard has a screen containing $ n+1 $ slots numbered from $ 1 $ to $ n+1 $ from left to right. The $ n+1 $ slots are going to be filled with an array of non-negative integers $ [a_1,a_2,a_3,\ldots,a_{n+1}] $ . Chaneka, as the player, must assign $ a_{n+1} $ with an integer between $ 0 $ and $ m $ inclusive. Then, for each $ i $ from $ n $ to $ 1 $ , the value of $ a_i $ will be equal to the remainder of dividing $ a_{i+1} $ (the adjacent value to the right) by $ i $ . In other words, $ a_i = a_{i + 1} \bmod i $ .
Chaneka wants it such that after every slot is assigned with an integer, there are exactly $ k $ distinct values in the entire screen (among all $ n+1 $ slots). How many valid ways are there for assigning a non-negative integer into slot $ n+1 $ ?
Input Format
Each test contains multiple test cases. The first line contains an integer $ t $ ( $ 1 \leq t \leq 2\cdot10^4 $ ) — the number of test cases. The following lines contain the description of each test case.
The only line of each test case contains three integers $ n $ , $ m $ , and $ k $ ( $ 1 \leq n \leq 10^9 $ ; $ 0 \leq m \leq 10^9 $ ; $ 1 \leq k \leq n+1 $ ) — there are $ n+1 $ slots, the integer assigned in slot $ n+1 $ must not be bigger than $ m $ , and there should be exactly $ k $ distinct values.
Output Format
For each test case, output a line containing an integer representing the number of valid ways for assigning a non-negative integer into slot $ n+1 $ .
Explanation/Hint
In the first test case, one of the $ 2 $ possible ways for Chaneka is to choose $ a_{n+1}=6 $ . If she does that, then:
- $ a_4=a_5\bmod 4=6\bmod 4=2 $
- $ a_3=a_4\bmod 3=2\bmod 3=2 $
- $ a_2=a_3\bmod 2=2\bmod 2=0 $
- $ a_1=a_2\bmod 1=0\bmod 1=0 $
- $ a = [0, 0, 2, 2, 6] $
- There are $ 3 $ distinct values.
In the second test case, the $ 1 $ possible way for Chaneka is to choose $ a_{n+1}=0 $ . If she does that, then $ a = [0, 0, 0] $ . There is only $ 1 $ distinct value.
In the third test case, there is no possible way for assigning a non-negative integer into slot $ n+1 $ .