03-树1 树的同构 （C语言链表实现）

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <string.h>
  4 #include <stdbool.h>
  5
  6 typedef char ElemType;
  7
  8 typedef struct BinTree
  9 {
 10     ElemType data;
 11     struct BinTree *left;
 12     struct BinTree *right;
 13 }BinTree;
 14
 15
 16 bool TreeCmp(BinTree * a, BinTree * b); //判断a树与b树是否同构
 17 BinTree * BinTree_new(int n);
 18
 19 int main()
 20 {
 21     int n;
 22     scanf("%d", &n);
 23     BinTree * a = BinTree_new(n);
 24     scanf("%d", &n);
 25     BinTree * b = BinTree_new(n);
 26
 27     bool flag = TreeCmp(a, b);
 28     if (flag)
 29         printf("Yes");
 30     else
 31         printf("No");
 32
 33     return 0;
 34 }
 35
 36 BinTree * BinTree_new(int n)
 37 {
 38     if (n == 0)
 39     {
 40         return  NULL;
 41     }
 42     else
 43     {
 44         int i, li, ri;
 45         ElemType c, lc, rc;
 46         BinTree * T = (BinTree *)malloc(n * sizeof(BinTree));
 47         bool *head = (bool *)malloc(n * sizeof(bool));
 48
 49         memset(head, true ,sizeof(head));
 50
 51         for ( i = 0; i < n ; ++i )
 52         {
 53             scanf(" %c %c %c", &c, &lc, &rc);
 54
 55             li = lc-‘0‘;
 56             ri = rc-‘0‘;
 57
 58             T[i].data = c;
 59
 60             if (lc != ‘-‘)
 61             {
 62                 T[i].left = &T[li];
 63                 head[li] = false;
 64             }
 65             else
 66                 T[i].left = NULL;
 67
 68             if (rc != ‘-‘)
 69             {
 70                 T[i].right = &T[ri];
 71                 head[ri] = false;
 72             }
 73             else
 74                 T[i].right = NULL;
 75
 76         }
 77
 78         //寻找树的树根（树根没有其它的结点指向它）
 79         for ( i = 0; i < n ; ++i )
 80             if (head[i] == true)
 81                 break;
 82         free(head);
 83         return &T[i];
 84     }
 85 }
 86
 87 bool TreeCmp(BinTree * a, BinTree * b)
 88 {
 89     if (a == NULL && b == NULL)//两棵树都为空
 90         return true;
 91
 92     if (a == NULL || b == NULL)//有一棵树为空
 93         return false;
 94
 95     if (a->data != b->data)//树结点的值不相等
 96         return false;
 97
 98     if (a->left == NULL && b->left == NULL)//两棵树的左子树都为空
 99         return TreeCmp(a->right, b->right);//就比较右子树
100
101     //两棵树的左子树都不为空，且两个值相等就比较两棵树的子树
102     if (a->left != NULL && b->left != NULL &&(a->left->data == b->left->data))
103         return (TreeCmp(a->left,b->left)&&TreeCmp(a->right,b->right));
104
105     //交换后再比较
106     else
107         return (TreeCmp(a->left,b->right)&&TreeCmp(a->right,b->left));
108 }