二叉树的建立、四种遍历、求深度、求叶子结点数
1 #include<stdio.h> 2 #include<stdlib.h> 3 typedef struct Node{ 4 struct Node *lchild, *rchild; 5 char data; 6 }BiNode, *BiTree; 7 BiTree CreatBiTree(BiTree *T)//前序建树,输入的是扩展二叉树 8 { 9 char a; 10 scanf("%c", &a); 11 if(a == '#') *T = NULL; 12 else{ 13 *T = (BiNode *)malloc(sizeof(BiNode)); 14 (*T)->data = a; 15 CreatBiTree(&(*T)->lchild); 16 CreatBiTree(&(*T)->rchild); 17 } 18 return *T; 19 } 20 void PreOrder(BiTree T) 21 { 22 if(T){ 23 printf("%c ", T->data); 24 PreOrder(T->lchild); 25 PreOrder(T->rchild); 26 } 27 } 28 void InOrder(BiTree T) 29 { 30 if(T){ 31 InOrder(T->lchild); 32 printf("%c ", T->data); 33 InOrder(T->rchild); 34 } 35 } 36 void PostOrder(BiTree T) 37 { 38 if(T){ 39 PostOrder(T->lchild); 40 PostOrder(T->rchild); 41 printf("%c ", T->data); 42 } 43 } 44 void LevelOrder(BiTree T)//注意这里开的队列一定要是结构体型，因为要寻左右孩子 45 { 46 BiNode *q[100]; 47 int front=0, rear=0; 48 q[rear++] = T; 49 while(front != rear){ 50 BiNode *t = q[front++]; 51 printf("%c ", t->data); 52 if(t->lchild) q[rear++] = t->lchild; 53 if(t->rchild) q[rear++] = t->rchild; 54 } 55 } 56 int cal_depth(BiTree T)//求深度，思想是求出左右深度，再用大的加一 57 { 58 if(!T) return 0; 59 else{ 60 int h1 = cal_depth(T->lchild); 61 int h2 = cal_depth(T->rchild); 62 return h1>h2? h1+1:h2+1;//所以是先等两个调用出结果，再计算本层的深度 63 } 64 } 65 int cal_leaves1(BiTree T, int *num)//第二个形参好像必须要有 66 { 67 if(!T->lchild&&!T->rchild) (*num)++; 68 else{ 69 if(T->lchild) cal_leaves1(T->lchild, num); 70 if(T->rchild) cal_leaves1(T->rchild, num); 71 } 72 return *num;//返回值要么不变要吗+1。返回值可以省略成void 73 } 74 int cal_leaves2(BiTree T)//*没想到 * 75 { 76 if(!T) return 0; 77 else if(!T->lchild&&!T->rchild) return 1; 78 else { 79 return cal_leaves2(T->lchild)+cal_leaves2(T->rchild); 80 } 81 } 82 int main() 83 { 84 BiTree T; 85 T = CreatBiTree(&T); 86 PreOrder(T); 87 printf("---前序遍历 "); 88 InOrder(T); 89 printf("---中序遍历 "); 90 PostOrder(T); 91 printf("---后序遍历 "); 92 LevelOrder(T); 93 printf("---层次遍历 "); 94 95 printf("二叉树深度：%d ", cal_depth(T)); 96 int n = 0; 97 printf("叶子结点数(算法1)：%d ", cal_leaves1(T, &n)); 98 printf("叶子结点数(算法2)：%d ", cal_leaves2(T)); 99 return 0; 100 }
测试数据1：abc##de#f##g###
