typedef struct kvpair {
  unsigned key;
  struct kvpair *right;
} kvpair;

kvpair *tsearch(kvpair tree[], unsigned key)
{
  for (;;) {
    if (!tree || (key == tree->key)) return tree;
    if (key < tree->key) {
      tree++;
    } else {
      tree = tree->right;
    }
  }
}