最简单的二叉树

typedef struct TNode
{
    int have_value;
    int v;
    struct TNode *left, *right;
} Node;

Node *root;

Node* newNode() {
    Node *u = (Node *)malloc(sizeof(Node));
    if ( u != NULL ) {
        u -> have_value = 0;
        u -> left = u -> right = NULL;
    }
    return u;
}

void addNode( int v ) {
    Node *n = newNode();
    n -> v = v;
    Node *c = root;
    while (1) {
        if ( v <= c->v ) {
            if ( c->left != NULL ) c = c->left;
            else {
                c->left = n;
                break;
            }
        }
        else {
            if ( c->right != NULL ) c = c->right;
            else {
                c->right = n;
                break;
            }
        }
    }
}

void printNodes(Node *n) {
    if ( n->left != NULL ) printNodes( n->left );
    printf("%d ",n->v);
    if ( n->right != NULL ) printNodes( n->right );
}

int main() {
    root = newNode();
    root->v = 50;
    for ( int i = 0; i < 1<<6; i++ ) {
        addNode(rand()%100);
    }
    printNodes(root);

    return 0;
}

 

广度优先查找:

void printNodesBFS() {
    int frount = 0, rear = 1;
    Node *q[(1<<6)+1];
    q[0] = root;
    while ( frount < rear ) {
        Node *_n = q[frount++];
        printf("%d ", _n->v);
        if ( _n->left != NULL ) q[rear++] = _n->left;
        if ( _n->right != NULL) q[rear++] = _n->right;
    }
    printf("\n");
}