longest consecutive sequence solution

Author: bhan

longest-consecutive-sequence/byol-han.js

@@ -0,0 +1,27 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var longestConsecutive = function (nums) {
+  if (nums.length === 0) return 0;
+
+  const numSet = new Set(nums);
+  let longest = 0;
+  for (let num of numSet) {
+    // `num - 1`이 없으면 새로운 수열의 시작점
+    if (!numSet.has(num - 1)) {
+      let count = 1;
+      let currentNum = num;
+
+      // 연속된 숫자 찾기
+      while (numSet.has(currentNum + 1)) {
+        currentNum++;
+        count++;
+      }
+
+      longest = Math.max(longest, count);
+    }
+  }
+
+  return longest;
+};