add 2017&2016

code_tree_2017.cpp

@@ -0,0 +1,39 @@
+#include<stdio.h>
+#include <stdlib.h>
+typedef struct node {
+    char data[10];
+    struct node* left, * right;
+}BTree;
+
+void midQuation(BTree* T) {
+    if (T != NULL && T->data[0] != '@') {
+        char t = T->data[0];
+        bool flag = false;
+        flag = (t == '+' || t == '-' || t == '*' || t == '/');
+        if (flag)printf("(");
+        if (T->left != NULL)midQuation(T->left);
+        for (int i = 0;T->data[i] != '\0';i++) {
+            printf("%c", T->data[i]);
+        }
+        if (T->right != NULL)midQuation(T->right);
+        if (flag)printf(")");
+    }
+}
+
+void createTree(BTree* node, char c[], int pos, int length) {
+    if (pos < length) {//填入数据
+        node->data[0] = c[pos];
+        node->data[1] = '\0';
+        node->left = (BTree*)malloc(sizeof(BTree));
+        node->right = (BTree*)malloc(sizeof(BTree));
+        createTree(node->left, c, pos * 2 + 1, length);
+        createTree(node->right, c, pos * 2 + 2, length);
+    }
+}
+
+int main() {
+    BTree* a = (BTree*)malloc(sizeof(BTree));
+    createTree(a, "*+*abc-@@@@@@@d@@@@@@@@@@@@@@@@", 0, 31);
+    midQuation(a);
+    return 0;
+}