求树的高度的递归和非递归方法
我觉得树的知识大家也不陌生,这里直接上代码得了.
非递归的方法是采用了中序遍历的非递归方式:
1 #include <stdio.h> 2 #include <stdlib.h> 3 4 #define MAX 100 5 6 #define ARRAY_SIZE(array, type) (sizeof(array) / sizeof(type)) 7 8 typedef struct node { 9 int value; 10 struct node* left; 11 struct node* right; 12 struct node* parent; 13 } node; 14 15 typedef struct t_node { 16 node* p; 17 int height; 18 } t_node; 19 20 void insert_node(node** root, int value) { 21 node* p = (node*)malloc(sizeof(node)); 22 if (NULL == p) { 23 fprintf(stderr, "malloc memory failed!\n"); 24 exit(1); 25 } 26 p->value = value; 27 p->left = p->right = p->parent = NULL; 28 29 if (NULL == *root) { 30 *root = p; 31 } 32 else { 33 node* q = *root; 34 node* r = NULL; 35 36 while (q != NULL) { 37 r = q; 38 if (q->value > p->value) { 39 q = q->left; 40 } 41 else if (q->value < p->value) { 42 q = q->right; 43 } 44 else { 45 return; 46 } 47 } 48 49 p->parent = r; 50 51 if (r->value > p->value) { 52 r->left = p; 53 } 54 else { 55 r->right = p; 56 } 57 } 58 } 59 60 void pre_order(node* root) { 61 if (root != NULL) { 62 fprintf(stderr, "%d\n", root->value); 63 pre_order(root->left); 64 pre_order(root->right); 65 } 66 } 67 68 int get_height(node* root) { 69 t_node stack[MAX]; 70 int pos = -1; 71 int cur = 0; 72 int max = 0; 73 74 while (root != NULL || pos != -1) { 75 if (root == NULL) { 76 root = stack[pos].p; 77 cur = stack[pos].height; 78 --pos; 79 root = root->right; 80 } 81 else { 82 ++pos; 83 ++cur; 84 stack[pos].p = root; 85 stack[pos].height = cur; 86 root = root->left; 87 } 88 89 if (cur > max) { 90 max = cur; 91 } 92 } 93 94 return max; 95 } 96 97 int main(void) { 98 int array[] = {5, 8, 3, 10, 2, 1, 0, 32, 321, 222, 11}; 99 int i = 0; 100 node* root = NULL; 101 102 for (; i < ARRAY_SIZE(array, int); ++i) { 103 insert_node(&root, array[i]); 104 } 105 106 int height = get_height(root); 107 108 fprintf(stderr, "%d\n", height); 109 110 111 return 0; 112 }
递归方法采用的是前序遍历的递归方式:
1 #include <stdio.h> 2 #include <stdlib.h> 3 4 #define ARRAY_SIZE(array, type) (sizeof(array) / sizeof(type)) 5 6 typedef struct node { 7 int value; 8 struct node* left; 9 struct node* right; 10 struct node* parent; 11 } node; 12 13 void insert_node(node** root, int value) { 14 node* p = (node*)malloc(sizeof(node)); 15 if (NULL == p) { 16 fprintf(stderr, "malloc memory failed!\n"); 17 exit(1); 18 } 19 p->value = value; 20 p->left = p->right = p->parent = NULL; 21 22 if (*root == NULL) { 23 *root = p; 24 } 25 else { 26 node* q = *root; 27 node* r = NULL; 28 while (q != NULL) { 29 r = q; 30 if (q->value > p->value) { 31 q = q->left; 32 } 33 else if (q->value < p->value) { 34 q = q->right; 35 } 36 else { 37 return; 38 } 39 } 40 41 p->parent = r; 42 if (r->value > p->value) { 43 r->left = p; 44 } 45 else { 46 r->right = p; 47 } 48 } 49 } 50 51 void pre_order(node* root) { 52 if (root != NULL) { 53 fprintf(stderr, "%d\n", root->value); 54 pre_order(root->left); 55 pre_order(root->right); 56 } 57 } 58 59 void get_height(node* root, int now, int* max) { 60 if (root != NULL) { 61 ++now; 62 if (now > *max) { 63 *max = now; 64 } 65 66 get_height(root->left, now, max); 67 get_height(root->right, now, max); 68 } 69 } 70 71 int main(void) { 72 int array[] = {5, 3, 4, 1, 2, 0, -1, -2, 9, 21, 7, 6, 5, 22, 23, 24, 25}; 73 74 node* root = NULL; 75 int i = 0; 76 for (; i < ARRAY_SIZE(array, int); ++i) { 77 insert_node(&root, array[i]); 78 } 79 80 pre_order(root); 81 82 int max = 0; 83 int now = 0; 84 85 get_height(root, now, &max); 86 87 fprintf(stderr, "%d\n", max); 88 89 return 0; 90 }
