longest consecutive sequence solution

Author: hyer0705

longest-consecutive-sequence/hyer0705.ts

@@ -0,0 +1,22 @@
+function longestConsecutive(nums: number[]): number {
+  if (nums.length === 0) return 0;
+
+  const numSet = new Set<number>(nums);
+  let longest = 0;
+
+  for (const num of numSet) {
+    if (!numSet.has(num - 1)) {
+      let currentNum = num;
+      let sequenceLength = 1;
+
+      while (numSet.has(currentNum + 1)) {
+        currentNum++;
+        sequenceLength++;
+      }
+
+      longest = Math.max(longest, sequenceLength);
+    }
+  }
+
+  return longest;
+}