Apartment Residents
InterviewTime limit0.5sMemory limit128 MB
Compute the resident count in room n on floor k, defined by repeated prefix sums starting from room i having i residents on floor 0.
- Level
Easy3 of 10
- Topics
- Dynamic programming, Math, Recursion
- Solved
- No attempts yet
Problem
An apartment starts at floor 0, and every floor has rooms numbered from 1. On floor 0, room i has exactly i residents.
For floors 1 and above, the number of residents in room b on floor a is the sum of the residents in rooms 1 through b on the floor directly below, floor (a - 1).
Given several queries k and n, find how many residents live in room n on floor k when every room follows this rule.
Input
The first line contains the number of test cases, T. For each test case, an integer k and an integer n are given on separate lines.
Output
For each test case, print the number of residents in room n on floor k, one answer per line.
Constraints
- 1 ≤
k≤ 14 - 1 ≤
n≤ 14