Question

Modify the code (that recognizes words ending with ing) to a code that recognizes the keywords if, then and else. In case it recognizes if it should output KEYWORD_IF,… If the word is not recognized, it should return an ERROR message.
Scanner scan = new Scanner(System.in);
String s = scan.next();
int q = 0;
for (char c : s.toCharArray()) {
switch (q) {
case 0: q = (c=='i')? 1 : 0; break;
case 1: q = (c=='n')? 2 : ((c=='i')? 1 : 0); break;
case 2: q = (c=='g')? 3 : ((c=='i')? 1 : 0); break;
case 3: q = (c=='i')? 1 : 0;
}
}
if (q==3)
System.out.println("accept.");
else
System.out.println("reject.");

Answer 1

Screenshot:

Code:

import java.io.*;
import java.util.*;

public class Main
{
   public static void main(String[] args) {
        //Scanner Object for user input
        Scanner scan=new Scanner(System.in);
        String s = scan.next();
         int n=s.length();
         //if word length is greater than or equal to 3 and end with ing then word is accept else rejected
            if (n>=3 && s.charAt(n-3)=='i'&& s.charAt(n-2)=='n'&& s.charAt(n-1)=='g')
            System.out.println("accept.");
            else
            System.out.println("reject.");
  
   }
}