longest-consecutive-sequence solution

Author: froggy1014

longest-consecutive-sequence/froggy1014.js

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+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+
+// 시간복잡도: O(n)
+var longestConsecutive = function (nums) {
+  let longest = 0;
+
+  let set = new Set(nums);
+
+  for (let num of nums) {
+    if (set.has(num - 1)) {
+      continue;
+    }
+
+    let count = 1;
+    let currentNum = num;
+
+    while (set.has(currentNum + 1)) {
+      count++;
+      currentNum++;
+    }
+    longest = Math.max(longest, count);
+  }
+  return longest;
+};
+
+console.log(longestConsecutive([100, 4, 200, 1, 3, 2])); // 4
+console.log(longestConsecutive([0, 3, 7, 2, 5, 8, 4, 6, 0, 1])); // 9
+console.log(longestConsecutive([1, 0, 1, 2])); // 3