LongestConsecutiveTest - longestConsecutive

src/test/java/LongestConsecutiveTest.java

@@ -0,0 +1,29 @@
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.HashSet;
+import java.util.Set;
+import org.junit.jupiter.api.Test;
+
+public class LongestConsecutiveTest {
+
+    @Test
+    void longestConsecutive() {
+        int[] nums = {100, 4, 200, 1, 3, 2};
+        Set<Integer> numSet = new HashSet<>();
+        for (int n : nums) {
+            numSet.add(n);
+        }
+        int longest = 0;
+        for (int n : nums) {
+            if (numSet.contains(n - 1)) {
+                continue;
+            }
+            int seq = 1;
+            while (numSet.contains(n + seq)) {
+                seq++;
+            }
+            longest = Math.max(longest, seq);
+        }
+        assertThat(longest).isEqualTo(4);
+    }
+}