写了个tostring

homework4/BiTree.cpp

@@ -1,4 +1,5 @@
 #include "BiTree.h"
+#include <sstream>
 
 bool BiTree::is_empty(BiTree *bt) {
     if (bt == nullptr) {
@@ -43,3 +44,22 @@ void BiTree::insertNode(BiTree*& bt, int value) {
         }
     }
 }
+
+
+void toStringHelper(const BiTree *node, std::ostringstream &oss, const std::string &prefix, bool isLeft) {
+    if (node != nullptr) {
+        oss << prefix;
+
+        oss << (isLeft ? "|--" : "|--") << node->data << "\n";
+
+        std::string newPrefix = prefix + (isLeft ? "|   " : "    ");
+        toStringHelper(node->left, oss, newPrefix, true);
+        toStringHelper(node->right, oss, newPrefix, false);
+    }
+}
+
+std::string BiTree::toString() {
+    std::ostringstream oss;
+    toStringHelper(this, oss, "", false);
+    return oss.str();
+}

homework4/BiTree.h

@@ -1,6 +1,7 @@
 #ifndef BITREE_H
 #define BITREE_H
 
+#include<sstream>
 
 
 class BiTree {
@@ -10,12 +11,17 @@ public:
     BiTree *right;
 
     static bool is_empty(BiTree *bt);
+
     static bool is_leaf(BiTree *bt);
+
     static int sum_leaf(BiTree *bt);
+
     static BiTree *createNode(int data);
+
     static void insertNode(BiTree *&bt, int value);
+
+    std::string toString();
 };
 
 
-
 #endif //BITREE_H

homework4/test1.cpp

@@ -1,12 +1,11 @@
 /*
- *二叉树采用二叉链存储结构存放，结点值为int 类型，设计一个递归算法求二叉树 bt 中所有叶子结点值之和
+ *二叉树采用二叉链存储结构存放，结点值为int 类型，设计一个递归算法求二叉树 bt 中所有叶子结点值之和
  */
 #include<iostream>
 #include"BiTree.h"
 using namespace std;
 
 
-
 BiTree *createTreeFromArray(const int *values, int size) {
     BiTree *root = nullptr;
     for (int i = 0; i < size; ++i) {
@@ -21,6 +20,7 @@ int main() {
 
     BiTree *root = createTreeFromArray(testValues, size);
 
-    cout << "Sum of leaf nodes: " << BiTree::sum_leaf(root) << endl;
+    cout << "树结构为：" << endl << root->toString() << endl;
+    cout << "叶子节点之和为: " << BiTree::sum_leaf(root) << endl;
     return 0;
 }