question: public static String compressChars ( String s , char c ) { int len = s . length ( ) ; StringBuilder sb = new StringBuilder ( len ) ; boolean wasChar = false ; for ( int i = 0 ; i < len ; i ++ ) { char c1 = s . charAt ( i ) ; if ( c1 == c ) { if ( wasChar ) { continue ; } wasChar = true ; } else { wasChar = false ; } sb . append ( c1 ) ; } if ( sb . length ( ) == len ) { return s ; } return sb . toString ( ) ; }
target:  Compress multiple occurrences of given char into one appearance.