longest consecutive sequence solved

Author: sora0319

longest-consecutive-sequence/sora0319.java

@@ -0,0 +1,32 @@
+import java.util.*;
+
+class Solution {
+    public int longestConsecutive(int[] nums) {
+        Set<Integer> checkList = new HashSet<>();
+        int seqCnt = 0;
+        int start = Integer.MIN_VALUE;
+
+        for(int n : nums){
+            checkList.add(n);
+        }
+
+        for (int n : nums) {
+            int seq = 1;
+            int target = n+1;
+            if(checkList.contains(n-1))continue;
+
+            while(checkList.contains(target)){
+                checkList.remove(target);
+                seq++;
+                target++;
+            }
+
+            if(seqCnt < seq){
+                seqCnt = seq;
+                start = n;
+            }
+        }
+        return seqCnt;
+    }
+}
+