c - Struct causing segmentation fault -

c - Struct causing segmentation fault -

i having problem grappling error. implementing reddish black tree in c , running segmentation fault @ particular location (line 29)

tnode *tree_add(tnode *root, const key k, const value v) { lnode *lnode = null; if (root == null) { tnode *node = talloc(k); lnode = lalloc(v); node->head = lnode; node->tail = lnode; node->is_red = true; homecoming node; } if (strcmp(k, root->key) < 0) { root->left = tree_add(root->left, k, v); } else if (strcmp(k, root->key) > 0) { root->right = tree_add(root->right, k, v); } else { if (strcmp(k, root->key) == 0) { lnode = lalloc(v); root->tail->next = lnode; root->tail = lnode; root->tail->next = null; } } if (is_red(root->right) && !is_red(root->left)) { //is_red seg faulting root = rotate_left(root); } if (is_red(root->left) && is_red(root->left->left)) { root = rotate_right(root); } if (is_red(root->left) && is_red(root->right)) { flip_colors(root); } homecoming root; }

here is_red function:

bool is_red(const tnode *h) { bool is_red = h->is_red; homecoming is_red;

}

before implementing lastly 3 if statements convert bst rb tree, code works fine. weird when debugged is_red, variable is_red comes true. means not accessing restricted memory. however, seg fault homecoming is_red function , intotree_add.

for farther clarification, here tnode struct:

typedef struct tnode { key key; // search key binary search tree node. struct tnode *right; // right child. struct tnode *left; // left child. lnode *head; // head of linked list storing values search key. lnode *tail; // tail of linked list storing values search key. bool is_red; // flag utilize in red-black trees denote redness. } tnode;

you want create sure right kid , left kid exist before is_red check: replace

if (is_red(root->right) && !is_red(root->left)) //is_red giving me seg fault

with

if (root->right && is_red(root->right) && root->left && !is_red(root->left))

please similar check other places.

c segmentation-fault red-black-tree