#include <stdio.h>#include <stdlib.h>typedef struct TreeNode { char data; struct TreeNode *left; struct TreeNode *right; } TreeNode, *PtrToNode;PtrToNode createBinaryTree() { char c; scanf("%c", &c); if (c == ' ') { return NULL; } PtrToNode node = (PtrToNode) malloc(sizeof(TreeNode)); node->data = c; node->left = createBinaryTree(); node->right = createBinaryTree(); return node;}int calculate(PtrToNode root) { if (root->left == NULL && root->right == NULL) { return root->data - '0'; } int left = calculate(root->left); int right = calculate(root->right); switch (root->data) { case '+': return left + right; case '-': return left - right; case '*': return left * right; case '/': return left / right; default: return 0; }}int main() { printf("请输入表达式，以回车结束：\n"); PtrToNode root = createBinaryTree(); printf("该表达式的计算结果为：%d\n", calculate(root)); return 0;}电脑运行的命令框显示输入式子后，按回车键无法显示结果，请改正

可以在读取字符后再读取一个字符，用来消耗掉输入式子后的回车符。修改后的代码如下：

#include <stdio.h>
#include <stdlib.h>

typedef struct TreeNode {
    char data;
    struct TreeNode *left;
    struct TreeNode *right;
} TreeNode, *PtrToNode;

PtrToNode createBinaryTree() {
    char c;
    scanf("%c", &c);
    if (c == ' ') {
        return NULL;
    }
    PtrToNode node = (PtrToNode) malloc(sizeof(TreeNode));
    node->data = c;
    node->left = createBinaryTree();
    node->right = createBinaryTree();
    return node;
}

int calculate(PtrToNode root) {
    if (root->left == NULL && root->right == NULL) {
        return root->data - '0';
    }
    int left = calculate(root->left);
    int right = calculate(root->right);
    switch (root->data) {
        case '+':
            return left + right;
        case '-':
            return left - right;
        case '*':
            return left * right;
        case '/':
            return left / right;
        default:
            return 0;
    }
}

int main() {
    printf("请输入表达式，以回车结束：\n");
    PtrToNode root = createBinaryTree();
    getchar(); // 消耗掉回车符
    printf("该表达式的计算结果为：%d\n", calculate(root));
    return 0;
}