Remove Comments

this problem needs to be dealed character by character each line, as there’re multi-cases.

I just copy one solution here.

PS: new followers increase.

Steps:
Iterate each line from the input document.
Inside the line, iterate each character of this line, check below conditions one by one
if in scope & meet “/”: you are not in scope from now
if in scope & meet “//”: add the string to list
if in scope: add character to the string, then if it is the end of the line, add the string to list
if NOT in scope & meet “/”: you are in scope again, then if it is last 2 characters of line, add the string to list
Summary:
If in scope, you have to beware if signs of “/” or “//” first.
Otherwise, you can collect the characters.
If not in scope, you have to beware if signs of “/” to get you back to scope

import java.util.ArrayList;
import java.util.List;

class Solution {

    private void addStToList(List<String> rl , StringBuilder sb){
        if(sb.length()>0){
            rl.add(sb.toString());
            sb.setLength(0);
        }
    }

    public List<String> removeComments(String[] source) {
        List<String> rl = new ArrayList<>();

        boolean inScope = true;
        StringBuilder sb = new StringBuilder();

        for (String line : source) {
            char[] ar = line.toCharArray();
            int m = ar.length;
            int i = 0;
            while (i < m) {
                // System.out.println("char="+ar[i]);
                if(inScope&&(i +1<m)&&("/*".equals(line.substring(i, i + 2)))){
                    inScope=false;
                    i+=2;
                }else if(inScope&&(i +1<m)&&("//".equals(line.substring(i, i + 2)))){
                    addStToList(rl, sb);
                    break;
                }else if(inScope){
                    sb.append(ar[i]);
                    if(i==m-1) addStToList(rl, sb);
                    i++;
                }else if(!inScope&& (i +1<m) && ("*/".equals(line.substring(i, i + 2))) ){
                    inScope=true;
                    if(i==m-2) addStToList(rl, sb);
                    i+=2;
                }else{
                    i++;
                }
                
            }

        }


        return rl;

    }
}