Merge branch 'main' into main

Author: SjxSubham

.github/pull_request_template.md

@@ -0,0 +1,32 @@
+###  Intuition
+<!-- Explain your thought process and initial approach to the problem -->
+
+
+
+
+### Approach
+<!-- Describe your solution approach in detail -->
+
+
+
+## Code Solution (C++)
+
+```cpp
+    // Your code goes here
+    
+
+```
+
+
+
+
+##  Related Issues
+<!-- Link any related issues: Closes #issue_number -->
+
+
+
+**By submitting this PR, I confirm that:**
+- [ ] This is my original work not totally AI genearted
+- [ ] I have tested the solution thoroughly on leetcode
+- [ ] I have maintained proper PR description format
+- [ ] This is a meaningful contribution, not spam

152. Maximum-Product-Subarray.cpp

@@ -0,0 +1,26 @@
+// 152. Maximum Product Subarray
+// By Traversing in Both Directions 
+// Time Complexity - O(n) and Space Complexity - O(1) 
+class Solution {
+public:
+    int maxProduct(vector<int>& nums) {
+        int n = nums.size();
+        int maxi = INT_MIN;
+        int ltr = 1, rtl = 1;
+        for(int i=0; i<n; i++){
+            if(ltr == 0){
+                ltr = 1;
+            }
+            if(rtl == 0){
+                rtl = 1;
+            }
+
+            ltr *= nums[i];
+            int j = n-i-1;
+            rtl *= nums[j];
+
+            maxi = max({ltr,rtl,maxi});
+        }
+        return maxi;
+    }
+};

2894. Divisible and Non-Divisible SumDifferences.cpp

@@ -0,0 +1,12 @@
+class Solution {
+public:
+    int differenceOfSums(int n, int m) {
+        int ans=0;
+        for(int i=1;i<=n;i++){
+            if(i%m==0) ans-=i;
+            else ans+=i;
+
+        }
+        return ans;
+    }
+};

355. Design Twitter.cpp

@@ -0,0 +1,48 @@
+class Twitter {
+private:
+    int time;
+    unordered_map<int, unordered_set<int>> mp; // Stores followers
+    unordered_map<int, vector<pair<int, int>>> mp2; // Stores tweets (time, tweetId)
+public:
+    Twitter() {
+        time=0;
+    }
+    
+    void postTweet(int userId, int tweetId) {
+        mp2[userId].emplace_back(time,tweetId);
+        time++;
+    }
+    
+    vector<int> getNewsFeed(int userId) {
+        priority_queue<pair<int,int>> pq;
+        for(auto i: mp2[userId]) pq.push(i);
+        for(auto i: mp[userId]){
+            for(auto j: mp2[i]) pq.push(j);
+        }
+        vector<int> feed;
+        int count=10;
+        while(!pq.empty() && count){
+            feed.push_back(pq.top().second);
+            pq.pop();
+            count--;
+        }
+        return feed;
+    }
+    
+    void follow(int followerId, int followeeId) {
+        mp[followerId].insert(followeeId);
+    }
+    
+    void unfollow(int followerId, int followeeId) {
+    mp[followerId].erase(followeeId); 
+}
+};
+
+/**
+ * Your Twitter object will be instantiated and called as such:
+ * Twitter* obj = new Twitter();
+ * obj->postTweet(userId,tweetId);
+ * vector<int> param_2 = obj->getNewsFeed(userId);
+ * obj->follow(followerId,followeeId);
+ * obj->unfollow(followerId,followeeId);
+ */