#include <bits/stdc++.h> using namespace std; typedef string ElemType; typedef struct BitNode { ElemType data; struct BitNode *lchild,*rchild; } BitNode,*BiTree; //char sc[10]= {"+-*/"}; void CreateBiTree(BiTree &t) { string ch; cin >> ch; if(ch[0] == '#') t = NULL; else { t = new BitNode; t->data = ch; CreateBiTree(t->lchild); CreateBiTree(t->rchild); } } void InOrderTraverse(BiTree t) { if(t) { string op = t->data; if(op[0]<'0' || op[0]>'9') cout << '('; InOrderTraverse(t->lchild); cout << t->data ; InOrderTraverse(t->rchild); if(op[0]<'0' || op[0]>'9') cout << ')'; } /***********************************/ } int main() { BiTree tree = new BitNode; string ch; while(cin >> ch) { tree->data = ch; CreateBiTree(tree->lchild); CreateBiTree(tree->rchild); InOrderTraverse(tree); printf("\n"); } return 0; }换为c语言

把代码中的头文件改为标准C语言的头文件，去掉using namespace std，把string改为char数组，去掉注释，把printf改为printf_s（或者使用头文件stdio.h中的printf函数）等等，修改后的代码如下：

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

typedef char ElemType;

typedef struct BitNode {
    ElemType data;
    struct BitNode *lchild,*rchild;
} BitNode,*BiTree;

void CreateBiTree(BiTree *t) {
    char ch;
    scanf("%c", &ch);
    if(ch == '#')
        *t = NULL;
    else
    {
        *t = (BitNode*)malloc(sizeof(BitNode));
        (*t)->data = ch;
        CreateBiTree(&((*t)->lchild));
        CreateBiTree(&((*t)->rchild));
    }
}

void InOrderTraverse(BiTree t) {
    if(t) {
        char op = t->data;
        if(op < '0' || op > '9') {
            printf("(");
        }
        InOrderTraverse(t->lchild);
        printf("%c", t->data);
        InOrderTraverse(t->rchild);
        if(op < '0' || op > '9') {
            printf(")");
        }
    }
}

int main() {
    BiTree tree = NULL;
    char ch;
    while(scanf("%c", &ch) != EOF) {
        tree = (BitNode*)malloc(sizeof(BitNode));
        tree->data = ch;
        CreateBiTree(&(tree->lchild));
        CreateBiTree(&(tree->rchild));
        InOrderTraverse(tree);
        printf_s("\n");
    }
    return 0;
}