1# Philippe's simple example 2#-------------------------- 3# 1 <= i <= N 4# 1 <= j <= N 5# 1 <= k <= N 6# i+j+k-2 = M 7#-------------------------- 87 7 9# i j k N M 1 101 1 0 0 0 0 -1 111 -1 0 0 1 0 0 121 0 1 0 0 0 -1 131 0 -1 0 1 0 0 141 0 0 1 0 0 -1 151 0 0 -1 1 0 0 160 -1 -1 -1 0 1 2 17#-------------------------- 180 4 19 20N M 21Philippe's simple example 22 23#-------------------------- 24# I have done the work by hand, and here is the right 25# answer : 26# 27# If 1 <= M <= N then EP(N,M) = 1/2 M^2 + 1/2 M 28# If N <= M <= 2N-1 then EP(N,M) = -3/2 N^2 - M^2 + 3NM - M 29# If 2N-1 <= M <= 3N-2 then EP(N,M) = 9/2 N^2 + 1/2 M^2 - 3NM - 3/2 N + 1/2 M 30