Corrections
This commit is contained in:
parent
bae88b22d7
commit
fcfaaa6e2d
10
luku25.tex
10
luku25.tex
|
@ -209,7 +209,7 @@ is as follows:
|
|||
\end{tikzpicture}
|
||||
\end{center}
|
||||
|
||||
Surprisingly enough, in this game,
|
||||
Surprisingly, in this game,
|
||||
all even-numbered states are winning states,
|
||||
and all odd-numbered states are losing states.
|
||||
|
||||
|
@ -256,7 +256,7 @@ $[10,12,5]$ is $10 \oplus 12 \oplus 5 = 3$,
|
|||
so the state is a winning state.
|
||||
|
||||
But how is the nim sum related to the nim game?
|
||||
We can explain this by studying how the nim
|
||||
We can explain this by looking at how the nim
|
||||
sum changes when the nim state changes.
|
||||
|
||||
~\\
|
||||
|
@ -395,7 +395,7 @@ The \key{Grundy number} for a game state is
|
|||
\[\textrm{mex}(\{g_1,g_2,\ldots,g_n\}),\]
|
||||
where $g_1,g_2,\ldots,g_n$ are Grundy numbers for
|
||||
states to which we can move from the state,
|
||||
and the mex function returns the smallest
|
||||
and the mex function gives the smallest
|
||||
nonnegative number that is not in the set.
|
||||
For example, $\textrm{mex}(\{0,1,3\})=2$.
|
||||
If there are no possible moves in a state,
|
||||
|
@ -787,10 +787,10 @@ For example, when $n=8$, the possibilities
|
|||
are $1+7$, $2+6$ and $3+5$, so
|
||||
\[f(8)=\textrm{mex}(\{f(1) \oplus f(7), f(2) \oplus f(6), f(3) \oplus f(5)\}).\]
|
||||
|
||||
In this game, the value of $f(n)$ is based on values
|
||||
In this game, the value of $f(n)$ is based on the values
|
||||
of $f(1),\ldots,f(n-1)$.
|
||||
The base cases are $f(1)=f(2)=0$,
|
||||
because it is not possible to divide heaps
|
||||
because it is not possible to divide the heaps
|
||||
of 1 and 2 sticks.
|
||||
The first Grundy numbers are:
|
||||
\[
|
||||
|
|
Loading…
Reference in New Issue