如何将字符串标记存储到数组中

question:
write a program that accepts string tokens in the format of token1:token2:token3:token4 , where : is used as delimiter to separate tokens. there should be two functions, ingest and appearance.

ingest takes a string, and stores it in the collection.

appearance takes a string as input . it returns a normalized value
between 0 to 1,  where the value represents the percentage of
appearances of stored tokens which have input as the prefix.

state the space and time complexity of your solution.

ingest('mcdonal:uk:employeea')
ingest('mcdonal:hk:employeea')
ingest('mcdonal:hk:employeeb')
ingest('mcdonal:hk:employeec')
ingest('fastfood')

appearance('mcdonal')
# > 0.8
appearance('mcdonal:hk')
# > 0.6

String input;
   
        
 // For user input
 Scanner sentense = new Scanner(System.in);
 input = sentense.nextLine();   
 String[] ingestWords = {};
       
             
 // Use ':' to seperate input
 StringTokenizer st = new StringTokenizer(input, ":");
 while(st.hasMoreTokens()) { 
   System.out.println(st.nextToken());
 }

public static void main(string[] args) {
    string input;
    list<string> ingestwords = new arraylist<>();

    scanner sentence = new scanner(system.in);
        
    while (sentence.hasnext()) {
        input = sentence.next();
            
        if (input.equals("exit")) { // to stop receiving input
            break;
        }
            
        ingestwords.add(input);         
    }
    sentence.close();
}

void hasPrefix(String word, String str) {
    return word.startsWith(str);
}