221. Big Bishops
time limit per test: 0.25
sec.
memory limit per test: 65536
KB
input: standard
output: standard
A bishop is a piece used in the game of chess which is played on a board of square grids. A bishop can only move diagonally from its current position and two bishops attack each other if one is on the path of the other.
Given two numbers n and k, your job is to determine the number of ways one can put k bishops on an n × n chessboard so that no two of them are in attacking positions.
Input
The input file contains two integers n (1 ≤ n ≤ 50) and k (0 ≤ k ≤ n^{2}).
Output
Print a line containing the total number of ways one can put the given number of bishops on a chessboard of the given size so that no two of them are in attacking positions.
Sample test(s)
Input
Test #1
4 4
Test #2
8 6
Output
Test #1
260
Test #2
5599888
Author:  Andrew Stankevich

Resource:  Little Chess Pieces Series, SPb IFMO 20032004 Authumn Training Sessions

Date:  20030927

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