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POc++ accidentally static linked list
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copied!<p>I've got a linked list class and for some reason when I increment an int in one object e.g linked1.size for some reason linked2.size also increments!</p> <p>And ideas why this is? I didn't intentionally make it a static variable.</p> <p>my code:</p> <pre><code>main() { Vlist v1; v1.add(1,0); v1.add(2,0); Vlist v2; } </code></pre> <p>Incrementing the size member variable occurs in the <code>add()</code> function like this: </p> <pre><code>(*this).size++; </code></pre> <p>The result should be the v1.size==2 and v2.size==0, but instead v2.size==2!</p> <p>This problem has been driving me crazy for hours- any help would be really appreciated!</p> <p>The add function is as follows:</p> <pre><code>int Vlist::quietAdd(Vertex new_vertex, int i_loc) { Vnode* temp= first_node; Vnode* newNode= NULL; //check for unique if (find(new_vertex)!=999) return 0; //check for non-negative i value if (i_loc<0) { cout<<"Invalid index."<<endl; return 0; } //and exit here? else { temp = find(i_loc); newNode= new Vnode(); if (size==0) first_node= newNode; //assigning to the new vnode the new Vertex value (*newNode).updateVertex(new_vertex.getInt()); //the nxt pointer now points to the value it's replacing or NULL (*newNode).updateNextPoint(temp); if ((temp==NULL)&&size!=0) { //size-1 is used to get the pointer to the last value on the list (*newNode).updatePrevPoint(find(size-1)); (*find((size-1))).updateNextPoint(newNode); } if (temp !=NULL) { //the new vnode's prev pointer now points to correct location (*newNode).updatePrevPoint((*temp).getPrevPoint()); if ((*temp).getPrevPoint()!=NULL) /*the vnode that used to point to the existing vnode now points to new vnode*/ (*((*temp).getPrevPoint())).updateNextPoint(newNode); //the old one's prev pointer points back to the new value (*temp).updatePrevPoint(newNode); } /*if we've just put a new vnode at the start then it should be pointed to by the "first vnode" pointer*/ if (i_loc==0) first_node=newNode; (*this).size++; } return 1; } //Vlist class definition class Vlist { private: int size; Vnode* first_node; public: //copy constructor Vlist(const Vlist& vl2):size(vl2.size), first_node(NULL) { for (int i=0;i<size;i++) quietAdd(vl2.read(i),i); } Vertex getNext(); Vlist (): size(0) { first_node=0; } ~Vlist (){};//make deep! bool empty(); Vnode* find(int i_loc) const; int find(Vertex target)const; void add(Vertex new_vertex, int i_loc); int quietAdd(Vertex new_vertex, int i_loc); Vertex remove(int i_loc); Vertex read(int i_loc) const; Vnode* getFirstNode() {return first_node;} int getSize() const { return size;} void setSize(int newSize) { size = newSize;} char* print() const; void delete_List(); }; class Vnode { private: Vertex vertex; Vnode* prev_node; Vnode* nxt_node; public: Vnode () : prev_node(0), nxt_node(0) { vertex.update(0); } ~Vnode (){}; //destructor Vertex getVertex(){return vertex;} int getVertexInt() { return vertex.getInt();} Vertex getNext(){return (*nxt_node).getVertex();} Vnode* getNextPoint() { return nxt_node; } Vnode* getPrevPoint() { return prev_node; } void updateNextPoint(Vnode* newP) { nxt_node = newP;} void updatePrevPoint(Vnode* newP) {prev_node= newP;} void updateVertex(Vertex vertexVal) {vertex.update(vertexVal.getInt());} }; </code></pre>

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