49 - ZOJ Monthly, December 2005 - 1002
A plane partition is a two-dimensional array of integers ni,j that are nonincreasing both from left to right and top to bottom. In other words,
ni,j <= ni,j+1
Implicit in this definition is the requirement that the array be flush on top and to the left and contain no holes.
For example, one plane partition of 22 is illustrated above and the corresponding two-dimensional array is
5 4 2 1 1
Now given 3 integers a, b, c, how many plane partitions whose diagrams fit inside an a * b rectangle and whose heights do not exceed c(in other words, with all ni,j <= c)?
Each line contains 3 integers - a, b, c(0 < a, b, c <= 6). The input ends with EOF.
Output the total number in one line for each test case.
1 1 1 2 2 2 3 3 3
2 20 980
Author: ZHANG, Zheng