add solution: Longest Consecutive Sequence

Author: GotPrgmer

longest-consecutive-sequence/Gotprgmer.java

@@ -0,0 +1,29 @@
+import java.util.*;
+class SolutionGotprgmer {
+    public int longestConsecutive(int[] nums) {
+        Set<Integer> set = new HashSet<>();
+        for(int num:nums){
+            set.add(num);
+        }
+        System.out.println(set);
+        int answer = 0;
+        for(int num:nums){
+            //왼쪽으로 확장
+            int left = 0;
+            while(set.contains(num-(left+1))){
+                left += 1;
+            }
+
+            //오른쪽으로 확장
+            int right = 0;
+            while(set.contains(num+right+1)){
+                right += 1;
+            }
+            System.out.println(String.valueOf(left)+" " + String.valueOf(right));
+            answer = Math.max(answer,left+right+1);
+        }
+
+        return answer;
+
+    }
+}