2023-01-07 update: added "2047. Number of Valid Words in a Sentence"

Author: fartem

README.md

@@ -355,6 +355,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2032. Two Out of Three                                                   | [Link](https://leetcode.com/problems/two-out-of-three/)                                                   | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/TwoOutOfThree.java)                                                |
 | 2037. Minimum Number of Moves to Seat Everyone                           | [Link](https://leetcode.com/problems/minimum-number-of-moves-to-seat-everyone/)                           | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/MinimumNumberOfMovesToSeatEveryone.java)                           |
 | 2042. Check if Numbers Are Ascending in a Sentence                       | [Link](https://leetcode.com/problems/check-if-numbers-are-ascending-in-a-sentence/)                       | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/CheckIfNumbersAreAscendingInASentence.java)                        |
+| 2047. Number of Valid Words in a Sentence                                | [Link](https://leetcode.com/problems/number-of-valid-words-in-a-sentence/)                                | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/NumberOfValidWordsInASentence.java)                                |
 | 2053. Kth Distinct String in an Array                                    | [Link](https://leetcode.com/problems/kth-distinct-string-in-an-array/)                                    | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/KthDistinctStringInAnArray.java)                                   |
 | 2057. Smallest Index With Equal Value                                    | [Link](https://leetcode.com/problems/smallest-index-with-equal-value/)                                    | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/SmallestIndexWithEqualValue.java)                                  |
 | 2062. Count Vowel Substrings of a String                                 | [Link](https://leetcode.com/problems/count-vowel-substrings-of-a-string/)                                 | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/CountVowelSubstringsOfAString.java)                                |

src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/NumberOfValidWordsInASentence.java

@@ -0,0 +1,69 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+// https://leetcode.com/problems/number-of-valid-words-in-a-sentence/
+public class NumberOfValidWordsInASentence {
+
+    private final String input;
+
+    public NumberOfValidWordsInASentence(String input) {
+        this.input = input;
+    }
+
+    public int solution() {
+        int result = 0;
+        for (String word : input.split("\\s+")) {
+            if (word.isEmpty()) {
+                continue;
+            }
+            if (checkFirstRule(word) && checkSecondRule(word) && checkThirdRule(word)) {
+                result++;
+            }
+        }
+        return result;
+    }
+
+    private boolean checkFirstRule(String token) {
+        for (int i = 0; i < token.length(); i++) {
+            char curr = token.charAt(i);
+            if (Character.isDigit(curr)
+                    || (Character.isLetter(curr) && Character.isUpperCase(curr))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean checkSecondRule(String token) {
+        int n = token.length();
+        int count = 0;
+        for (int i = 0; i < n; i++) {
+            if (token.charAt(i) == '-') {
+                count++;
+                if (count > 1) {
+                    break;
+                }
+                if (i == 0 || i == n - 1) {
+                    return false;
+                }
+                if (!Character.isLetter(token.charAt(i - 1))
+                        || !Character.isLetter(token.charAt(i + 1))) {
+                    return false;
+                }
+            }
+        }
+        return count < 2;
+    }
+
+    private boolean checkThirdRule(String token) {
+        for (int i = 0; i < token.length() - 1; i++) {
+            char curr = token.charAt(i);
+            if (!Character.isLetter(curr)
+                    && !Character.isDigit(curr) && curr != '-') {
+                return false;
+            }
+        }
+        return true;
+
+
+    }
+}

src/test/java/com/smlnskgmail/jaman/leetcodejava/easy/NumberOfValidWordsInASentenceTest.java

@@ -0,0 +1,21 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class NumberOfValidWordsInASentenceTest {
+
+    @Test
+    public void defaultTests() {
+        assertEquals(3, new NumberOfValidWordsInASentence("cat and  dog").solution());
+        assertEquals(0, new NumberOfValidWordsInASentence("!this  1-s b8d!").solution());
+        assertEquals(
+                5,
+                new NumberOfValidWordsInASentence(
+                        "alice and  bob are playing stone-game10"
+                ).solution()
+        );
+    }
+
+}