C语言实现16进制到2进制的转换

绝地灬酷狼 2022-05-26 02:50 332阅读 0赞

### 今天帮同学看代码，她想实现把16进制的数转换成2进制显示，百度了一下，代码是不少，但是都太长了，想起C和指针里面有似曾相识的东西，就自己写了一下，还是遇到了一些问题。 ###

##### 1. 没有注意到字符串存储的时候后面会自动加一个\\0，因此想存放一个长度为n的字符串，需要开辟n + 1 个字节的空间，最后一个字节存放\\0. #####

##### 2. 循环过程中注意循环变量每次迭代过程中都要想终止条件靠近，避免死循环. #####

##### 3.利用数组下标的控制来模拟栈 #####

### 废话太多了，下面给出源码： ###

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    
    void
    HextoTwo(int num)
    {
        int res;
        int i = 0;
        char buf[BUFSIZ][5] = {
       "0000"};
        char reference[16][5] = {
       "0000","0001","0010","0011",\
                            "0100","0101","0110","0111",\
                            "1000","1001","1010","1011",\
                            "1100","1101","1110","1111"};
    
        while(num / 16 !=  0)
        {
            res = num % 16;
            strcpy(buf[i++], reference[res]);
            num = num / 16;
        }
    
        res = num % 16;
        strcpy(buf[i++], reference[res]);
    
        while(i > 0)
            printf("%s ", buf[--i]);
    }
    
    int main()
    {
        int num = 0xfa;
        HextoTwo(num);
        return EXIT_SUCCESS;
    }

### 下面给出递归解法，话说天才用递归，然而本人很菜……. ###

void
    HextoTwo(int num)
    {
        int remainder;
        char buf[16][5] = {
       "0000","0001","0010","0011",\
                            "0100","0101","0110","0111",\
                            "1000","1001","1010","1011",\
                            "1100","1101","1110","1111"};
        if(0 == num)
            return;
    
        remainder = num % 16;
        HextoTwo(num >> 4);
        printf("%s ", buf[remainder]);
    }

### 就这么简单，还是要多写代码多思考，算法没有形成之前不要动手。 ###