[reach0908] WEEK 01 solutions

longest-consecutive-sequence/reach0908.js

@@ -0,0 +1,31 @@
+/**
+ * @description
+ * time complexity: O(n log n)
+ * space complexity: O(n)
+ * runtime: 57ms
+ * 풀이 방법: 중복을 제거하고 정렬한 다음에 연속된 숫자의 개수를 카운트하여 최대값을 반환한다.
+ * @param {number[]} nums
+ * @return {number}
+ */
+const longestConsecutive = function (nums) {
+  if (nums.length === 0) return 0;
+  const sortedNums = [...new Set(nums)].sort((a, b) => a - b);
+
+  let maxConsecutiveCount = 1;
+  let currentConsecutiveCount = 1;
+
+  for (let i = 1; i < sortedNums.length; i += 1) {
+    if (sortedNums[i] === sortedNums[i - 1] + 1) {
+      currentConsecutiveCount += 1;
+    } else {
+      currentConsecutiveCount = 1;
+    }
+
+    maxConsecutiveCount = Math.max(
+      maxConsecutiveCount,
+      currentConsecutiveCount
+    );
+  }
+
+  return maxConsecutiveCount;
+};