add 3606

Author: fishercoder1534

paginated_contents/algorithms/4th_thousand/README.md

@@ -20,6 +20,7 @@
 | 3978 | [Unique Middle Element](https://leetcode.com/problems/unique-middle-element/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3978.java) |                                                                               | Easy       |
 | 3701 | [Compute Alternating Sum](https://leetcode.com/problems/compute-alternating-sum/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3701.java) |                                                                               | Easy       |
 | 3662 | [Filter Characters by Frequency](https://leetcode.com/problems/filter-characters-by-frequency/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3662.java) |                                                                               | Easy       |
+| 3606 | [Coupon Code Validator](https://leetcode.com/problems/coupon-code-validator/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3606.java) |                                                                               | Easy       |
 | 3502 | [Minimum Cost to Reach Every Position](https://leetcode.com/problems/minimum-cost-to-reach-every-position/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3502.java) |                                                                               | Easy       |
 | 3491 | [Phone Number Prefix](https://leetcode.com/problems/phone-number-prefix/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3491.java) |                                                                               | Easy       |
 | 3477 | [Fruits Into Baskets II](https://leetcode.com/problems/fruits-into-baskets-ii/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3477.java) |                                                                               | Easy       |

src/main/java/com/fishercoder/solutions/fourththousand/_3606.java

@@ -0,0 +1,45 @@
+package com.fishercoder.solutions.fourththousand;
+
+import java.util.*;
+
+public class _3606 {
+    public static class Solution1 {
+
+        Set<String> validBiz = new HashSet<>(Arrays.asList("electronics", "grocery", "pharmacy", "restaurant"));
+
+        public List<String> validateCoupons(String[] code, String[] businessLine, boolean[] isActive) {
+            Map<String, List<String>> map = new HashMap<>();
+            for (int i = 0; i < code.length; i++) {
+                if (isValid(code[i], businessLine[i], isActive[i])) {
+                    List<String> list = map.getOrDefault(businessLine[i], new ArrayList<>());
+                    list.add(code[i]);
+                    map.put(businessLine[i], list);
+                }
+            }
+            TreeMap<String, List<String>> treeMap = new TreeMap<>();
+            for (Map.Entry<String, List<String>> entry : map.entrySet()) {
+                List<String> list = entry.getValue();
+                Collections.sort(list);
+                treeMap.put(entry.getKey(), list);
+            }
+            List<String> result = new ArrayList<>();
+            for (Map.Entry<String, List<String>> entry : treeMap.entrySet()) {
+                result.addAll(entry.getValue());
+            }
+            return result;
+        }
+
+        private boolean isValid(String code, String bizLine, boolean isActive) {
+            if (!isActive || !validBiz.contains(bizLine) || code.equals("")) {
+                return false;
+            }
+            for (char c : code.toCharArray()) {
+                if (Character.isAlphabetic(c) || Character.isDigit(c) || '_' == c) {
+                } else {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+}

src/test/java/com/fishercoder/fourththousand/_3606Test.java

@@ -0,0 +1,34 @@
+package com.fishercoder.fourththousand;
+
+import com.fishercoder.solutions.fourththousand._3606;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class _3606Test {
+    private _3606.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _3606.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        String[] code = new String[]{"SAVE20", "", "PHARMA5", "SAVE@20"};
+        String[] businessLine = new String[]{"restaurant", "grocery", "pharmacy", "restaurant"};
+        boolean[] isActive = new boolean[]{true, true, true, true};
+        assertEquals(Arrays.asList("PHARMA5", "SAVE20"), solution1.validateCoupons(code, businessLine, isActive));
+    }
+
+    @Test
+    public void test2() {
+        String[] code = new String[]{"GROCERY15", "ELECTRONICS_50", "DISCOUNT10"};
+        String[] businessLine = new String[]{"grocery", "electronics", "invalid"};
+        boolean[] isActive = new boolean[]{false, true, true};
+        assertEquals(Arrays.asList("ELECTRONICS_50"), solution1.validateCoupons(code, businessLine, isActive));
+    }
+}