Hi,

I am having issues with assigning a value to a string. I have two structures node and edge as follows:

struct node{
	string name;
	int key;
};

struct edge
{
	 node u;
	 node v;
	int weight; 
	edge *link; 
}*front = NULL;

Now I have a function that I am using to create a priority queue to order edges according to their weights, however whenever I try to assign a value to a name attribute of a node the program crashes:

void insert_pque(string a1, string a2, int i,int j,int wt) 
{
	edge *tmp,*q;
	tmp = (edge *)malloc(sizeof(edge)); 

	tmp->u.key=i;
        [B]tmp->v.name = a2; // CRASHES HERE!!! [/B]
	tmp->v.key=j; 
	tmp->weight = wt; 
...
}

When debugging crash message from memcpy.asm:

TrailUp1:
        mov     al,[esi]        ;U - get byte from source
                                ;V - spare
        mov     [edi],al        ;U - put byte in destination
        mov     eax,[dst]       ;V - return pointer to destination
        pop     esi             ;U - restore esi
        pop     edi             ;V - restore edi
        M_EXIT

When I use simple char as type for the name everything works fine, however when I try using strings it crashes ! :(

Any help would be much appreciated,
Thanks

Deflamol

You can't use malloc() to allocate c++ objects like std::string, but use the new operator. This is more than likely the cause of your program crashing.

Thank you for the reply Ancient Dragon,

Unfortunately I'm not sure on how to do that :

I tried doing this:

tmp->u.name = new string ();

But it didn't work... Any hints?

Again thank you very much

you don't specifically allocate memory for the string object because it is not a pointer inside the structure. Just allocate tmp and everything will be allocated ok tmp = new edge;

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