longest consecutive sequence solution

Author: smosco

longest-consecutive-sequence/smosco.js

@@ -0,0 +1,28 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+const longestConsecutive = (nums) => {
+  if (nums.length === 0) return 0;
+
+  const numSet = new Set(nums);
+  let maxLength = 0;
+
+  for (const num of numSet) {
+    // 시퀀스 시작점만 체크
+    if (!numSet.has(num - 1)) {
+      let currentNum = num;
+      let currentLength = 1;
+
+      // 연속된 숫자 카운트
+      while (numSet.has(currentNum + 1)) {
+        currentNum++;
+        currentLength++;
+      }
+
+      maxLength = Math.max(maxLength, currentLength);
+    }
+  }
+
+  return maxLength;
+};