Question

Write a function text_filter that takes two lists of characters and checks to see if all the characters in the first list are included in the second list AND in the same order, BUT possibly with other characters in between.

Done in OCAML

For example text_filter ['a';'m';'z'] ['1';'a';'2';'m';'3';'z'] = true text_filter ['a';'m';'z'] ['1';'a';'3';'z'] = false text_filter ['a';'m';'z'] ['1';'z';'2';'m';'3';'a'] = false

let rec text_filter (xs:char list) (ys:char list) : bool = *)

(* Problem 3b. Rewrite the function above so that is is polymorphic, i.e., it should work on lists whose elements are any types. Give at least one test case (call your function at least once) with a type that is different from chars. *)

Answer 1

i have included 2 test cases here

in test case one the characters in first list are included in the second list
in second test case the characters in second list contain the characters but in different order

public class HelloWorld{

public static boolean RegEx(char array1[], char array2[]){
int flag=-1;
for(int i=0;i<array1.length;i++){
for(int j=flag+1;j<array2.length;j++){
if(array1[i]==array2[j]){
flag=j;
if(i==array1.length-1){
return true;
}
break;
}
if(j==array2.length-1){
return false;
}
}
}
return false;
}

public static void main(String []args){
//char array1[] = {'a','b','c'};
//char array2[] = {'1','a','2','b','3','c'};
  
char array1[] = {'b','a','c'};
char array2[] = {'1','a','2','b','3','c'};

System.out.println(RegEx(array1,array2));
}
}