3, 4

Author: Sbeo-Joe

longest-consecutive-sequence/Sbeo_Joe.cpp

@@ -0,0 +1,23 @@
+class Solution {
+public:
+    int longestConsecutive(vector<int>& nums) {
+        if(nums.size() == 0) return 0;
+        set<int> us{nums.begin(), nums.end()};
+        int ret = 1;
+        vector<int> vec(us.begin(), us.end());
+        int prevNum = vec[0];
+        int ret_candi = 1;
+        for(int i = 1; i < vec.size(); i++){
+            if(vec[i] - vec[i-1] == 1){
+                ret_candi++;
+                ret = max(ret, ret_candi);
+                continue;
+            } else {
+                ret_candi = 1;
+                continue;
+            }
+        }
+
+        return ret;
+    }
+};

top-k-frequent-elements/Sbeo-Joe.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+    vector<int> topKFrequent(vector<int>& nums, int k) {
+        // value, count
+        unordered_map<int, int> um;
+        for(auto& n : nums){
+            um[n]++;
+        }
+
+        //value, count
+        vector<std::pair<int, int>> vec(um.begin(), um.end());
+        sort(vec.begin(), vec.end(), 
+            [](const auto& a, const auto& b) { return a.second > b.second;});
+
+        vector<int> ret;
+        for(int i=0; i< k; i++){
+            ret.push_back(vec[i].first);
+        }
+
+        return ret;
+    }
+};