C语言二叉树遍历操作

#include <stdio.h>#include <stdlib.h>#include <string.h> #define MAX_TREE_SIZE 80typedef struct bit_tree_node{unsigned int num;struct bit_tree_node *lchild,*rchild;}tree_node,*bit_tree;unsigned int create_tree(bit_tree *tree)//指针的指针{unsigned int num;printf("please input:\n");scanf("%d",&num);if(num == 0){return -1;}else{*tree =(bit_tree)malloc(sizeof(tree_node));memset(*tree,0,sizeof(tree_node));(*tree)->num = num;printf("please input %d's left child:",(*tree)->num);create_tree(&((*tree)->lchild));printf("please input %d's right child:",(*tree)->num);create_tree(&((*tree)->rchild));}return 0;}void pre_order(bit_tree tree)//前序遍历{if(tree != NULL){printf("%d,",tree->num);pre_order(tree->lchild);pre_order(tree->rchild);}}void in_order(bit_tree tree)//中序遍历{if(tree != NULL){pre_order(tree->lchild);printf("%d,",tree->num);pre_order(tree->rchild);}}void post_order(bit_tree tree)//后序遍历{if(tree != NULL){pre_order(tree->lchild);pre_order(tree->rchild);printf("%d,",tree->num);}}void print_tree(bit_tree tree,int layer){if(tree == NULL){return;}print_tree(tree->rchild,layer+1);for(int i=0;i<layer;i++){printf("----");}printf("%d\n",tree->num);print_tree(tree->lchild,layer+1);}void pre_tree(bit_tree tree)//前序非递归遍历{bit_tree stack[MAX_TREE_SIZE];int top = 0; while(tree != NULL||top!= 0){if(tree != NULL){printf("%d\n",tree->num);top++;stack[top] = tree;tree = tree->lchild;}else{tree = stack[top];top--;tree = tree->rchild;}}}void in_tree(bit_tree tree)//中序非递归遍历{bit_tree stack[MAX_TREE_SIZE];int top = 0; while(tree != NULL||top!= 0){if(tree != NULL){top++;stack[top] = tree;tree = tree->lchild;}else{tree = stack[top];top--;printf("%d\n",tree->num);tree = tree->rchild;}}}void post_tree1(bit_tree tree)//后序非递归遍历1{bit_tree stack[MAX_TREE_SIZE];int top = 0; bit_tree p = tree;bit_tree q = NULL;while(p != NULL || top != 0){while(p != NULL){top++;stack[top] = p;p = p->lchild;}if(top>0){p = stack[top];if(p->rchild == NULL || p->rchild == q){top--;printf("%d\n",p->num);q = p;p= NULL;}else{p = p->rchild;}}}}void post_tree2(bit_tree tree)//后序非递归遍历2{bit_tree stack[MAX_TREE_SIZE];int top = 0; bit_tree save[MAX_TREE_SIZE];int save_top = 0;while(tree != NULL||top!= 0){if(tree != NULL){save_top++;save[save_top] = tree;top++;stack[top] = tree;tree = tree->rchild;}else{tree = stack[top];top--;tree = tree->lchild;}}while(save_top !=0){printf("%d\n",save[save_top]->num);save_top--;}}void layer_tree(bit_tree tree)//层次遍历遍历{bit_tree queue[MAX_TREE_SIZE];int head = 0;int tail = 0;bit_tree tree_node;if(tree != NULL){queue[tail] = tree;tail++;}while(head != tail){tree_node = queue[head];head++;printf("%d\n",tree_node->num);if(tree_node->lchild != NULL){queue[tail] = tree_node->lchild;tail++;}if(tree_node->rchild != NULL){queue[tail] = tree_node->rchild;tail++;}}}void main(){bit_tree tree;create_tree(&tree);int choice = 0;while(choice != -1){scanf("%d",&choice);switch(choice){case 1:print_tree(tree,1);break;case 2:pre_order(tree);break;case 3:pre_tree(tree);break;case 4:post_tree1(tree);break;case 5:layer_tree(tree);break;case 7:in_tree(tree);break;case 8:post_tree2(tree);break;default:break;}}}