Trying to make a simple rectangle/bin packer in C. Takes a given area and finds placement for any given size rectangle. About after 4 recursions is when I get the segmentation fault. #include <stdio.h> #include <stdlib.h> typedef struct node_type PackNode; struct node_type { int x , y; int width , height; int used; struct node_type *left; struct node_type *right; }; typedef struct point_type PackPoint; struct point_type { int x,y; }; PackNode _clone(PackNode *node) { PackNode clone; clone.used = 0; clone.x = node->x; clone.y = node->y; clone.width = node->width; clone.height= node->height; clone.left = NULL; clone.right= NULL; return clone; } PackNode root; int rcount; PackPoint* recursiveFind(PackNode *node, int w, int h) { PackPoint rp; PackPoint *p = NULL; rcount++; printf ("rcount = %u\n", rcount); //left is not null go to left, if left didn't work try right. if (node->left!=NULL) { //move down to left branch p = recursiveFind(node->left, w, h); if (p!=NULL) { return p; } else { p = recursiveFind(node->right, w, h); return p; } } else { //If used just return null and possible go to the right branch; if (node->used==1 || w > node->width || h > node->height) { return p; } //if current node is exact size and hasn't been used it return the x,y of the mid-point of the rectangle if (w==node->width && h == node->height) { node->used=1; rp.x = node->x+(w/2); rp.y = node->y+(h/2); p = &rp; return p; } //If rectangle wasn't exact fit, create branches from cloning it's parent. PackNode l_clone = _clone(node); PackNode r_clone = _clone(node); node->left = &l_clone; node->right = &r_clone; //adjust branches accordingly, split up the current unused areas if ( (node->width - w) > (node->height - h) ) { node->left->width = w; node->right->x = node->x + w; node->right->width = node->width - w; } else { node->left->height = h; node->right->y = node->y + h; node->right->height = node->height - h; } p = recursiveFind(node->left, w, h); return p; } return p; } int main(void) { root = malloc( root.x=0; root.y=0; root.used=0; root.width=1000; root.height=1000; root.left=NULL; root.right=NULL; int i; PackPoint *pnt; int rw; int rh; for (i=0;i<10;i++) { rw = random()%20+1; rh = random()%20+1; pnt = recursiveFind(&root, rw, rh); printf("pnt.x,y: %d,%d\n",pnt->x,pnt->y); } return 0; }