Corrections

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Antti H S Laaksonen 2017-02-18 17:13:06 +02:00
parent bae88b22d7
commit fcfaaa6e2d
1 changed files with 5 additions and 5 deletions

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@ -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:
\[