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选择C++ source file 新建一个空白文档
首先声明头文件
定义树的结点结构 typedef struct TreeNode{ char data;/*树中结点的数据是一个字符*/ struct TreeNode *lchild; struct TreeNode *rchild;}TREENODE;
声明变量int NodeNum = 0;/*统计数的结点数*/int LeafNum = 0;/*统计数的叶子结点数*/char ch[] = {'a', 'b', 'c', ' ', ' ', 'd', ' ', ' ', 'e', 'f', ' ', ' ', 'g', ' ', ' '};int inc = 0;
用函数建立一个二叉树 int CreateBiTree(TREENODE **T)/*按先序次序输入二叉树中结点的值,以空字符表示空树*/{char i;if(ch[inc++]==' ') *T = NULL;else{printf('%c\n',ch[inc-1]);if(!(*T = (TREENODE *)malloc(sizeof(TREENODE)))) return -1;(*T)->data = ch[inc-1];printf('%c\n',(*T)->data);CreateBiTree(&((*T)->lchild));CreateBiTree(&((*T)->rchild));}return 1;}
先序遍历二叉树int PreOderTraverse(TREENODE *T){if(T){printf('%c ',T->data);PreOderTraverse(T->lchild);PreOderTraverse(T->rchild);}return 1;}
中序遍历二叉树int InOderTraverse(TREENODE *T){if(T){InOderTraverse(T->lchild);printf('%c ',T->data);InOderTraverse(T->rchild);}return 1;}
后序遍历二叉树int BackOderTraverse(TREENODE *T){if(T){BackOderTraverse(T->lchild);BackOderTraverse(T->rchild);printf('%c ',T->data);}return 1;}
利用先序遍历来计算树中的结点数void CountNodeNum(TREENODE *T){if(T){NodeNum ++;CountNodeNum(T->lchild);CountNodeNum(T->rchild);}}
利用先序遍历计算叶子节点数void CountLeafNum(TREENODE *T){if(T){if((!(T->lchild))&&(!(T->rchild))) LeafNum ++;CountLeafNum(T->lchild);CountLeafNum(T->rchild);}}
主函数int main(){TREENODE *T;int i;CreateBiTree(&T);do{ puts('**************************************************'); puts('* you can choose: *'); puts('* 1: Traverse the Binary tree by pre order *'); puts('* 2: Traverse the Binary tree by mid order *'); puts('* 3: Traverse the Binary tree by back order *'); puts('* 4: Count the node num of the Binary tree *'); puts('* 5: Count the leaf node num of the Binary tree*'); puts('**************************************************'); puts('please input your choice:'); scanf('%d',&i); switch(i) { case 1:printf('The preoder is:\n');PreOderTraverse(T);printf('\n');break;case 2:printf('The midoder is:\n');InOderTraverse(T);printf('\n');break;case 3:printf('The backoder is:\n');BackOderTraverse(T);printf('\n');break;case 4:CountNodeNum(T);printf('The nodenum of the tree is:%d\n',NodeNum);break;case 5:CountLeafNum(T);printf('The leafnum of the tree is:%d\n',LeafNum);break; } printf('please input any char to go on\n'); getch();}while((i>=1)&&(i<6)); getch();return 1;}
运行结果