Bad-Character-Heuristik

$\displaystyle \lambda$	:	$\displaystyle \Sigma$ $\displaystyle \to$ {0...\| m\|}
		c $\displaystyle \mapsto$ max $\displaystyle \left(\vphantom{ \{0\} \cup \{ i : 1\le i< k \wedge m[i]=c \} }\right.$ {0} $\displaystyle \cup$ {i : 1 $\displaystyle \le$ i < k $\displaystyle \wedge$ m[i] = c} $\displaystyle \left.\vphantom{ \{0\} \cup \{ i : 1\le i< k \wedge m[i]=c \} }\right)$