feat: Longest Consecutive Sequence

DaleStudy#240

Author: donghyeon95

longest-consecutive-sequence/donghyeon95.java

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+import java.util.HashSet;
+
+public class Solution {
+	public int longestConsecutive(int[] nums) {
+		HashSet<Integer> set = new HashSet<>();
+		for (int num : nums) {
+			set.add(num);
+		}
+
+		int maxStreak = 0;
+
+		for (int num : nums) {
+			// 내가 시작 값이라면
+			if (!set.contains(num - 1)) {
+				int currentNum = num;
+				int currentStreak = 1;
+
+				// 나로부터 연결되는 값을 찾는다.
+				while (set.contains(currentNum + 1)) {
+					currentNum++;
+					currentStreak++;
+				}
+
+				maxStreak = Math.max(maxStreak, currentStreak);
+			}
+		}
+
+		return maxStreak;
+	}
+}
+
+
+
+