1 #include<stdio.h> 2 #include<stdlib.h> 3 typedef struct node 4 { 5 int data; 6 struct node *l,*r; 7 8 }tree; 9 tree* Creattree(void)//層次建立二叉樹 10 { 11 int data,front=1,rear=0; 12 tree* t, *root, *q[1001]; 13 while(scanf("%d", &data),data!=-1) 14 { 15 if(data==0) 16 t = NULL; 17 else 18 { 19 t=(tree*)malloc(sizeof(tree)); 20 t->data=data; 21 t->l=NULL; 22 t->r=NULL; 23 } 24 rear++; 25 q[rear]=t;//元素入隊 26 if(rear==1) 27 root= t;//建立根結點 28 else 29 { 30 if(q[front]!=NULL) 31 { 32 if(rear%2==0) 33 q[front]->l = t;//偶數給左 34 else 35 q[front]->r = t;//奇數給右 36 } 37 if(rear%2==1)//保證兩個數都掛上樹了再換下一個結點 38 front++; 39 } 40 } 41 return root; 42 } 43 void preorder(tree *p)//這里只舉例前序遍歷，中序和后序前一張有 44 { 45 if(p==NULL) 46 return; 47 printf(" %d", p->data); 48 preorder(p->l); 49 preorder(p->r); 50 } 51 int main() 52 { 53 tree *t; 54 int n; 55 scanf("%d",&n); 56 while(n--) 57 { 58 t=Creattree(); 59 preorder(t); 60 printf("\n"); 61 } 62 return 0; 63 }