add 722 java

Author: yennanliu

README.md

@@ -620,7 +620,7 @@
 686 | [Repeated String Match](https://leetcode.com/problems/repeated-string-match/) | [Python](./leetcode_python/String/repeated-string-match.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/String/RepeatedStringMatch.java)| _O(n + m)_ | _O(1)_ | Medium |brute force, math, string, `Rabin-Karp Algorithm`, `google` | AGAIN**** (3) 
 696| [Count Binary Substrings](https://leetcode.com/problems/count-binary-substrings/) | [Python](./leetcode_python/String/count-binary-substrings.py) | _O(n)_ | _O(1)_ | Easy|good trick, linear scan, group sub-string, `amazon`| AGAIN******* (3) (MUST)
 720| [Longest Word in Dictionary](https://leetcode.com/problems/longest-word-in-dictionary/) | [Python](./leetcode_python/String/longest-word-in-dictionary.py) | _O(n)_ | _O(t)_ | Easy  | Trie | AGAIN (not start)
-722| [Remove Comments](https://leetcode.com/problems/remove-comments/) | [Python](./leetcode_python/String/remove-comments.py) | _O(n)_ | _O(k)_ | Medium || AGAIN (not start)
+722| [Remove Comments](https://leetcode.com/problems/remove-comments/) | [Python](./leetcode_python/String/remove-comments.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/String/RemoveComments.java)| _O(n)_ | _O(k)_ | Medium |string, google| AGAIN (1)
 734| [Sentence Similarity](https://leetcode.com/problems/sentence-similarity/) | [Python ](./leetcode_python/String/sentence-similarity.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/String/SentenceSimilarity.java) | _O(n + p)_ | _O(p)_| Easy |good basic, graph, `hash table`,`collections.defaultdict(set)` ,`google`| OK***** (5)
 751| [IP to CIDR](https://leetcode.com/problems/ip-to-cidr/) |[Python](./leetcode_python/String/ip-to-cidr.py) | _O(n)_ | _O(1)_ | Medium | `ip`| AGAIN (not start*)
 758| [Bold Words in String](https://leetcode.com/contest/weekly-contest-66/problems/bold-words-in-string/) | [Python](./leetcode_python/String/bold-words-in-string.py) | _O(n * l)_ | _O(t)_ |  Easy | 🔒, variant of [Add Bold Tag in String](https://leetcode.com/problems/add-bold-tag-in-string/) | AGAIN (not start)

data/progress.md

@@ -1,5 +1,8 @@
 # Progress
 
+# 2024-11-26
+- https://github.com/yennanliu/CS_basics/blob/master/doc/Leetcode_company_frequency-master/Google%206months-%20LeetCode.pdf
+
 # 2024-11-25
 - https://github.com/yennanliu/CS_basics/blob/master/doc/Leetcode_company_frequency-master/Google%206months-%20LeetCode.pdf
 

data/progress.txt

@@ -1,3 +1,4 @@
+20241126: 722
 20241125: 33,81
 20241124: 153
 20241123: 253

data/to_review.txt

@@ -1,3 +1,4 @@
+2025-01-20 -> ['722']
 2025-01-19 -> ['33,81']
 2025-01-17 -> ['253']
 2025-01-16 -> ['776,31']
@@ -8,6 +9,7 @@
 2025-01-04 -> ['53,210,207']
 2025-01-03 -> ['444']
 2025-01-02 -> ['1188,130,855(again)']
+2024-12-30 -> ['722']
 2024-12-29 -> ['33,81']
 2024-12-28 -> ['900']
 2024-12-27 -> ['253', '26,27', '802,1197,26']
@@ -17,22 +19,24 @@
 2024-12-21 -> ['394', '855,846']
 2024-12-20 -> ['833,950', '932']
 2024-12-18 -> ['951,792']
+2024-12-17 -> ['722']
 2024-12-16 -> ['33,81']
 2024-12-14 -> ['253', '53,210,207', '163,1048']
 2024-12-13 -> ['776,31', '444', '298,729']
 2024-12-12 -> ['004(todo),34(todo),162(todo),275(todo)', '1188,130,855(again)', '1146']
 2024-12-11 -> ['986(todo),1229(todo),1868(todo),80(todo),209(todo),283(todo),360(todo),713(todo),532(todo),611(todo)']
+2024-12-09 -> ['722']
 2024-12-08 -> ['33,81', '394', '737']
 2024-12-07 -> ['833,950', '900', '686,734,737']
 2024-12-06 -> ['253', '26,27', '802,1197,26', '353']
 2024-12-05 -> ['776,31', '528,334']
-2024-12-04 -> ['004(todo),34(todo),162(todo),275(todo)']
+2024-12-04 -> ['722', '004(todo),34(todo),162(todo),275(todo)']
 2024-12-03 -> ['33,81', '986(todo),1229(todo),1868(todo),80(todo),209(todo),283(todo),360(todo),713(todo),532(todo),611(todo)', '1145']
-2024-12-01 -> ['253', '53,210,207']
+2024-12-01 -> ['722', '253', '53,210,207']
 2024-11-30 -> ['33,81', '776,31', '394', '444', '855,846', '1145,1219']
-2024-11-29 -> ['004(todo),34(todo),162(todo),275(todo)', '833,950', '1188,130,855(again)', '932']
-2024-11-28 -> ['33,81', '253', '986(todo),1229(todo),1868(todo),80(todo),209(todo),283(todo),360(todo),713(todo),532(todo),611(todo)']
-2024-11-27 -> ['33,81', '776,31', '951,792', '524,221,889']
+2024-11-29 -> ['722', '004(todo),34(todo),162(todo),275(todo)', '833,950', '1188,130,855(again)', '932']
+2024-11-28 -> ['722', '33,81', '253', '986(todo),1229(todo),1868(todo),80(todo),209(todo),283(todo),360(todo),713(todo),532(todo),611(todo)']
+2024-11-27 -> ['722', '33,81', '776,31', '951,792', '524,221,889']
 2024-11-26 -> ['33,81', '253', '004(todo),34(todo),162(todo),275(todo)', '743,889']
 2024-11-25 -> ['253', '776,31', '986(todo),1229(todo),1868(todo),80(todo),209(todo),283(todo),360(todo),713(todo),532(todo),611(todo)', '394', '837']
 2024-11-24 -> ['253', '776,31', '004(todo),34(todo),162(todo),275(todo)', '833,950', '900']

leetcode_java/src/main/java/LeetCodeJava/String/RemoveComments.java

@@ -0,0 +1,84 @@
+package LeetCodeJava.String;
+
+import java.util.ArrayList;
+import java.util.List;
+
+// https://leetcode.com/problems/remove-comments/description/
+// https://leetcode.ca/all/722.html
+public class RemoveComments {
+
+    // V0
+    // TODO : implement
+//    public List<String> removeComments(String[] source) {
+//
+//    }
+
+    // V1
+    // IDEA : PARSING
+    // https://leetcode.com/problems/remove-comments/editorial/
+    public List<String> removeComments_1(String[] source) {
+        boolean inBlock = false;
+        StringBuilder newline = new StringBuilder();
+        List<String> ans = new ArrayList();
+        for (String line: source) {
+            int i = 0;
+            char[] chars = line.toCharArray();
+            if (!inBlock) {
+                newline = new StringBuilder();
+            }
+            while (i < line.length()) {
+                if (!inBlock && i+1 < line.length() && chars[i] == '/' && chars[i+1] == '*') {
+                    inBlock = true;
+                    i++;
+                } else if (inBlock && i+1 < line.length() && chars[i] == '*' && chars[i+1] == '/') {
+                    inBlock = false;
+                    i++;
+                } else if (!inBlock && i+1 < line.length() && chars[i] == '/' && chars[i+1] == '/') {
+                    break;
+                } else if (!inBlock) {
+                    newline.append(chars[i]);
+                }
+                i++;
+            }
+            if (!inBlock && newline.length() > 0) {
+                ans.add(new String(newline));
+            }
+        }
+        return ans;
+    }
+
+
+    // V2
+    // https://leetcode.ca/2017-11-21-722-Remove-Comments/
+    public List<String> removeComments_2(String[] source) {
+        List<String> ans = new ArrayList<>();
+        StringBuilder sb = new StringBuilder();
+        boolean blockComment = false;
+        for (String s : source) {
+            int m = s.length();
+            for (int i = 0; i < m; ++i) {
+                if (blockComment) {
+                    if (i + 1 < m && s.charAt(i) == '*' && s.charAt(i + 1) == '/') {
+                        blockComment = false;
+                        ++i;
+                    }
+                } else {
+                    if (i + 1 < m && s.charAt(i) == '/' && s.charAt(i + 1) == '*') {
+                        blockComment = true;
+                        ++i;
+                    } else if (i + 1 < m && s.charAt(i) == '/' && s.charAt(i + 1) == '/') {
+                        break;
+                    } else {
+                        sb.append(s.charAt(i));
+                    }
+                }
+            }
+            if (!blockComment && sb.length() > 0) {
+                ans.add(sb.toString());
+                sb.setLength(0);
+            }
+        }
+        return ans;
+    }
+
+}

leetcode_java/src/main/java/dev/workspace5.java

@@ -3966,6 +3966,44 @@ public boolean search(int[] nums, int target) {
         return false;
     }
 
+    // LC 722
+    // https://leetcode.com/problems/remove-comments/
+    // 7.41 pm - 8.15 pm
+    /**
+     *  Idea 1) string op
+     *      a tmp array that collect "Not comment" element,
+     *      then merge filtered elements as final result
+     */
+    public List<String> removeComments(String[] source) {
+
+        if (source.length == 0){
+            return new ArrayList<>();
+        }
+
+        List<String> tmp = new ArrayList<>();
+        //StringBuilder sb = new StringBuilder();
+        boolean isMuitLineComment = false;
+        for (String x : source){
+            System.out.println(">>> x = " + x);
+            if (x.contains("/*") && x.contains("*/")){
+                tmp.add(x.split("/*")[0]);
+                //tmp.add(x.split("*/\")[1]);
+                continue;
+            }
+            if (x.contains("/*")){
+                isMuitLineComment = true;
+            }else if (x.contains("*/")){
+                isMuitLineComment = false;
+            }
+            if (!x.contains("//") && !isMuitLineComment){
+                //sb.append(x);
+                tmp.add(x);
+            }
+        }
+
+        return tmp;
+    }
+
 }