二叉树的遍历

先序遍历

void PreorderTraversal( BinTree BT ){    if (BT){        printf(" %c",BT->Data);        PreorderTraversal(BT->Left);        PreorderTraversal(BT->Right);    }}

中序遍历

void InorderTraversal( BinTree BT ){    if (BT){        InorderTraversal(BT->Left);        printf(" %c",BT->Data);        InorderTraversal(BT->Right);    }}

后序遍历

void PostorderTraversal( BinTree BT ){    if (BT){        PostorderTraversal(BT->Left);        PostorderTraversal(BT->Right);        printf(" %c",BT->Data);    }}

层次遍历

（数组实现）

void LevelorderTraversal( BinTree BT ){    if (BT){        BinTree Q[100];        BinTree p;        int head=0,tail=0;        if (BT){            Q[tail++]=BT;            while (tail!=head){                p=Q[head++];                printf(" %c",p->Data);                if (p->Left) Q[tail++]=p->Left;                if (p->Right) Q[tail++]=p->Right;            }        }    }}

（队列实现）

void LevelOrder(Node *root) {      if(root == NULL) return;      queue<Node*> Q;      Q.push(root);      //while there is at least one discovered node      while(!Q.empty()) {          Node* current = Q.front();          Q.pop(); // removing the element at front          cout<<current->data<<" ";          if(current->left != NULL) Q.push(current->left);          if(current->right != NULL) Q.push(current->right);      }  }