text: countP [ ] : Store count of all characters of pattern countTW [ ] : Store count of current window of text
code: char countP [ MAX ] = { 0 } , countTW [ MAX ] = { 0 } ; for ( int i = 0 ; i < M ; i ++ ) { ( countP [ pat [ i ] ] ) ++ ; ( countTW [ txt [ i ] ] ) ++ ; }