为什么我的程序分步执行而不是正常执行？

Question

The idea of my project is to build a probability tree on a repeated experiment with several possible outcomes.

This is quite a simple project, and I think I did it right. It's a basic tree building : there's a building recursive function that determines node values and initializes children, and then build children.

Simplified code :

typedef struct Node {
    int depth;
    int noElements;
    float probability;
    struct Node *node0,*node1,*node4;
} Node;

void buildProbabilityTree(Node *node, int maxDepth) {
    node->child1=malloc(sizeof node->child1);
    //... set child1 values ...
    buildProbabilityTree(node->child1,maxDepth);

    node->child2=malloc(sizeof node->child2);
    //... set child2 values ...
    buildProbabilityTree(node->child2,maxDepth);

    node->child3=malloc(sizeof node->child3);
    //... set child3 values ...
    buildProbabilityTree(node->child3,maxDepth);
}

int main(int argc, char *argv[]) {

    Node root={0,0,1,NULL,NULL,NULL};
    buildProbabilityTree(&root,3);

    return EXIT_SUCCESS;
}

Full code (only 50 lines) http://pastie.org/private/cqiazmgp4bvexcidzlmutg

Problem is : it does not work!

I'm using Codeblock and GNU gcc compiler. When I run the step-to-step debug, program goes to the end with no problem. But when I build it without debugger, the program crashes when it reaches the "bottom" of the probability tree.

Anyone knows where that could come from ? A Code::Blocks option maybe ? A compiler issue ? Thanks.

Answer 1

(Decided to move comment to answer)

sizeof(node->node0) doesn't do what you think it does. You just malloc'd the size of a pointer, not your struct.

Change your malloc calls to allocate sizeof(Node) (or sizeof(*node->node0) ... though I think the former is easier on the eyes).

Answer 2

I think the problem is that you only malloc(sizeof Node *). So you are only allocating memory for a pointer which is not enough!

You should malloc(sizeof Node).

Try to change malloc(sizeof node->childx) to malloc(sizeof *node->childx).