Create 3508. Implement Router (#890)

Author: Chayandas07

3508. Implement Router

@@ -0,0 +1,71 @@
+class Router {
+public:
+    int limit = 0;
+    set<vector<int>> packets;
+    unordered_map<int, int> removedPacketsFromDestination;
+    unordered_map<int, vector<int>> pD;
+
+    queue<vector<int>> q;
+    Router(int memoryLimit) { limit = memoryLimit; }
+
+    bool addPacket(int source, int destination, int timestamp) {
+        if (packets.find({source, destination, timestamp}) != packets.end()) {
+            return false;
+        }
+        if (q.size() > 0) {
+
+            if (limit == q.size()) {
+
+                vector<int> p = q.front();
+
+                packets.erase(p);
+                removedPacketsFromDestination[p[1]]++;
+
+                q.pop();
+            }
+        }
+
+        q.push({source, destination, timestamp});
+        pD[destination].push_back(timestamp);
+        packets.insert({source, destination, timestamp});
+        return true;
+    }
+
+    vector<int> forwardPacket() {
+        if (q.size() > 0) {
+            vector<int> p = q.front();
+            packets.erase(p);
+            removedPacketsFromDestination[p[1]]++;
+            q.pop();
+            return p;
+        }
+
+        return {};
+    }
+
+    int getCount(int destination, int startTime, int endTime) {
+
+        if (pD.find(destination) == pD.end()) {
+            return 0;
+        }
+
+        int x = removedPacketsFromDestination[destination];
+
+        auto it = lower_bound(pD[destination].begin() + x,
+                              pD[destination].end(), startTime);
+
+        auto it2 = upper_bound(pD[destination].begin() + x,
+                               pD[destination].end(), endTime);
+
+        int count = int(it2 - it);
+        return count;
+    }
+};
+
+/**
+ * Your Router object will be instantiated and called as such:
+ * Router* obj = new Router(memoryLimit);
+ * bool param_1 = obj->addPacket(source,destination,timestamp);
+ * vector<int> param_2 = obj->forwardPacket();
+ * int param_3 = obj->getCount(destination,startTime,endTime);
+ */