src/main/java/com/fishercoder/solutions/_1410.java

package com.fishercoder.solutions;

/**
 * 1410. HTML Entity Parser
 *
 * HTML entity parser is the parser that takes HTML code as input and replace all the entities of the special characters by the characters itself.
 * The special characters and their entities for HTML are:
 * Quotation Mark: the entity is &quot; and symbol character is ".
 * Single Quote Mark: the entity is &apos; and symbol character is '.
 * Ampersand: the entity is &amp; and symbol character is &.
 * Greater Than Sign: the entity is &gt; and symbol character is >.
 * Less Than Sign: the entity is &lt; and symbol character is <.
 * Slash: the entity is &frasl; and symbol character is /.
 * Given the input text string to the HTML parser, you have to implement the entity parser.
 *
 * Return the text after replacing the entities by the special characters.
 *
 * Example 1:
 * Input: text = "&amp; is an HTML entity but &ambassador; is not."
 * Output: "& is an HTML entity but &ambassador; is not."
 * Explanation: The parser will replace the &amp; entity by &
 *
 * Example 2:
 * Input: text = "and I quote: &quot;...&quot;"
 * Output: "and I quote: \"...\""
 *
 * Example 3:
 * Input: text = "Stay home! Practice on Leetcode :)"
 * Output: "Stay home! Practice on Leetcode :)"
 *
 * Example 4:
 * Input: text = "x &gt; y &amp;&amp; x &lt; y is always false"
 * Output: "x > y && x < y is always false"
 *
 * Example 5:
 * Input: text = "leetcode.com&frasl;problemset&frasl;all"
 * Output: "leetcode.com/problemset/all"
 *
 * Constraints:
 * 1 <= text.length <= 10^5
 * The string may contain any possible characters out of all the 256 ASCII characters.
 * */
public class _1410 {
    public static class Solution1 {
        public String entityParser(String text) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < text.length(); i++) {
                if (text.charAt(i) != '&') {
                    sb.append(text.charAt(i));
                } else {
                    if (i + 7 <= text.length() && text.substring(i, i + 7).equals("&frasl;")) {
                        sb.append("/");
                        i += 6;
                    } else if (i + 6 <= text.length() && text.substring(i, i + 6).equals("&quot;")) {
                        sb.append("\"");
                        i += 5;
                    } else if (i + 6 <= text.length() && text.substring(i, i + 6).equals("&apos;")) {
                        sb.append("'");
                        i += 5;
                    } else if (i + 5 <= text.length() && text.substring(i, i + 5).equals("&amp;")) {
                        sb.append("&");
                        i += 4;
                    } else if (i + 4 <= text.length() && text.substring(i, i + 4).equals("&gt;")) {
                        sb.append(">");
                        i += 3;
                    } else if (i + 4 <= text.length() && text.substring(i, i + 4).equals("&lt;")) {
                        sb.append("<");
                        i += 3;
                    } else {
                        sb.append(text.charAt(i));
                    }
                }
            }
            return sb.toString();
        }
    }
}