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Author: chau-nm

2047-number-of-valid-words-in-a-sentence/2047-number-of-valid-words-in-a-sentence.java

@@ -0,0 +1,36 @@
+class Solution {
+    public int countValidWords(String sentence) {
+        String[] words = sentence.split(" ");
+        int count = 0;
+        for (String word : words) {
+            if (isToken(word)) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    public boolean isToken(String word) {
+        if (word.length() == 0) return false;
+        int hyphenCount = 0;
+        for (int i = 0; i < word.length(); i++) {
+            char ch = word.charAt(i);
+            if (ch >= '0' && ch <= '9') {
+                return false;
+            }
+            if (ch == '-') {
+                 if (i == 0 || i == word.length() - 1 || 
+                    (i > 0 && word.charAt(i - 1) != '-' && 
+                    !Character.isLowerCase(word.charAt(i - 1))) || 
+                    (i < word.length() - 1 && !Character.isLowerCase(word.charAt(i + 1)))) {
+                    return false;
+                }
+                hyphenCount++;
+            }
+            if ((ch == '.' || ch == ',' || ch == '!') && i < word.length() - 1) {
+                return false;
+            }
+        }
+        return hyphenCount <= 1;
+    }
+}