longest-consecutive-sequence solution

Author: rlawjd10

longest-consecutive-sequence/rlawjd10.cpp

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+class Solution {
+public:
+    int longestConsecutive(vector<int>& nums) {
+        unordered_map<int, int> count;
+		//  nums에 해당하는 index는 1을 표시
+        for (int num: nums) {
+            count[num] = 1;
+        }
+
+        vector<pair<int, int>> order(count.begin(), count.end());
+        sort(order.begin(), order.end(), [](auto& a, auto& b) {return a.first < b.first;});
+
+        int length = 1;
+        int currentLength = 1;
+        if(order.empty()) return 0;
+        for (int i = 1; i < order.size(); i++) {
+            // 연속적인지 확인
+            if (order[i].first == order[i-1].first +1)
+                currentLength++;
+            else
+                currentLength = 1;
+            length = max(length, currentLength);
+        }
+        
+        return length;
+    }
+};
+