#237 & #240 & #264 solutions

Author: ys-han00

house-robber/ys-han00.cpp

@@ -0,0 +1,24 @@
+class Solution {
+public:
+    int rob(vector<int>& nums) {
+        vector<int> dp(nums.size(), 0);
+
+        dp[0] = nums[0];
+        if(dp.size() == 1) 
+            return dp[0];
+        
+        dp[1] = nums[1];
+        int ans = max(dp[0], dp[1]);
+        
+        for(int i = 2; i < dp.size(); i++) {
+            int maxi = -1;
+            for(int j = 0; j < i - 1; j++)
+                maxi = max(dp[j], maxi);
+            dp[i] = maxi + nums[i];
+            ans = max(ans, dp[i]);
+        }
+
+        return ans;
+    }
+};
+

longest-consecutive-sequence/ys-han00.cpp

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+
+class Solution {
+public:
+    int longestConsecutive(vector<int>& nums) {
+        if(nums.size() == 0) 
+            return 0;
+
+        sort(nums.begin(), nums.end());
+
+        int ans = 1, cnt = 1;
+        for(int i = 1; i < nums.size(); i++) {
+            if(nums[i] == nums[i - 1])
+                continue;
+            if(nums[i] - 1 == nums[i - 1])
+                cnt++;
+            else
+                cnt = 1;
+            ans = max(cnt, ans);
+        }
+
+        return ans;
+    }
+};
+

top-k-frequent-elements/ys-han00.cpp

@@ -0,0 +1,29 @@
+#include <bits/stdc++.h>
+
+class Solution {
+public:
+    vector<int> topKFrequent(vector<int>& nums, int k) {
+        map<int, int> count;
+
+        for(int i = 0; i < nums.size(); i++) {
+            if(count.find(nums[i]) == count.end())
+                count[nums[i]] = 1;
+            else
+                count[nums[i]]++;
+        }
+
+        vector<pair<int, int>> cnt(count.begin(), count.end());
+        sort(cnt.begin(), cnt.end(), cmp);
+
+        vector<int> ans;
+        for(int i = 0; i < k; i++)
+            ans.push_back(cnt[i].first);
+        
+        return ans;
+    }
+
+    static bool cmp(const pair<int, int>& a, const pair<int, int>& b) {
+        return a.second > b.second;
+    }
+};
+