Time: 136 ms (45.73%), Space: 75.9 MB (10.51%) - LeetHub

Author: shahdhoss

0128-longest-consecutive-sequence/0128-longest-consecutive-sequence.cpp

@@ -0,0 +1,26 @@
+class Solution {
+public:
+    int longestConsecutive(vector<int>& nums) {
+        if(nums.empty()){
+            return 0;
+        }
+        sort(nums.begin(),nums.end());
+        vector<int> answer(nums.size(),1);
+        unordered_map<int,int> hashmap;
+        hashmap[nums[0]]=0;
+        for(int i=1;i<nums.size();i++){
+            hashmap[nums[i]]=i;
+            if(hashmap.count(nums[i]-1)>0){
+                int temp=hashmap[nums[i]-1];
+                answer[i]=max(answer[temp]+1,answer[i-1]);
+            }
+        }
+        int maximum=INT_MIN;
+        for(int i=0;i<answer.size();i++){
+            if(answer[i]>maximum){
+                maximum=answer[i];
+            }
+        }
+        return maximum;
+    }
+};