Traverse the string s Update arrays arr [ ] and brr [ ]
for ( var i = 0 ; i < n ; i ++ ) { arr [ s [ i ] . charCodeAt ( 0 ) - " " . charCodeAt ( 0 ) ] = s [ i ] ; brr [ s [ i ] . charCodeAt ( 0 ) - " " . charCodeAt ( 0 ) ] = s [ i ] ; }