Create 1670.Design-Front-Middle-Back-Queue_v1.cpp

Linked_List/1670.Design-Front-Middle-Back-Queue/1670.Design-Front-Middle-Back-Queue_v1.cpp

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+class FrontMiddleBackQueue {
+    int arr[1000];
+    int n = 0;
+public:
+    FrontMiddleBackQueue() {
+    }
+
+    void pushFront(int val) 
+    {
+        for (int i=n; i>=1; i--)
+            arr[i] = arr[i-1];
+        arr[0] = val;
+        n++;        
+    }
+
+    void pushMiddle(int val) 
+    {
+        int i = n-1;
+        for (int i=n; i>= max(1,n/2); i--)
+            arr[i] = arr[i-1];
+        arr[n/2] = val;
+        n++;        
+    }
+
+    void pushBack(int val) 
+    {
+        arr[n] = val;
+        n++;        
+    }
+
+    int popFront() 
+    {
+        if (n==0) return -1;
+        int ret = arr[0];
+        for (int i=0; i<n-1; i++)
+            arr[i] = arr[i+1];
+        n--;        
+        return ret;
+    }
+
+    int popMiddle() 
+    {
+        if (n==0) return -1;
+        int ret = arr[(n-1)/2];
+        for (int i=(n-1)/2; i<n; i++)
+            arr[i] = arr[i+1];
+        n--;        
+        return ret;
+    }
+
+    int popBack() 
+    {
+        if (n==0) return -1;
+        int ret = arr[n-1];
+        n--;        
+        return ret;
+    }
+};
+
+/**
+ * Your FrontMiddleBackQueue object will be instantiated and called as such:
+ * FrontMiddleBackQueue* obj = new FrontMiddleBackQueue();
+ * obj->pushFront(val);
+ * obj->pushMiddle(val);
+ * obj->pushBack(val);
+ * int param_4 = obj->popFront();
+ * int param_5 = obj->popMiddle();
+ * int param_6 = obj->popBack();
+ */