longest-consecutive-sequence solution

Author: yg-cho

longest-consecutive-sequence/Yg-cho.js

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+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var longestConsecutive = function(nums) {
+  if(nums.length === 0) return 0;
+
+  const numSet = new Set(nums);
+  let longest = 0;
+
+  for (const num of numSet) {
+    if(!numSet.has(num-1)) {
+      let currentNum = num;
+      let currentLength = 1;
+
+      while(numSet.has(currentNum+1)) {
+        currentNum++;
+        currentLength++;
+      }
+
+      longest = Math.max(longest, currentLength)
+    }
+  }
+  return longest;
+};