十进制、二进制、十六进制转换（面试题）原码 补码 python

1. 题目

用16位二进制数表示一个十进制数字，最高位是符号位（1表示负数，并且负数用补码表示）。编程实现：输入一个十进制数字，计算输出以英文逗号（,）分割的该数字的16位二进制字符串（不足16位时，前面补0）和4位十六进制字符串（不足4位时，前面补0，如果包含字符，用大写字母表示）。当输入数字超过最大值或最小值符时，输出“NODATA”字符，输入非数字字符时，输出“INPUTERROR”字符串。例如：输入15，输出00000000001111，000F；输入-1，输出1111111111111111，FFFF，输入A，输出输入非法。

2. 解答

使用python自带函数验证参考11111Python 二进制，十进制，十六进制转换

## 10-2 不管固定位数
def int2bin(n):  # 输入参数为整数
    bin2 = ''
    while n >0:
        a = n%2
        n = n//2
        bin2 = str(a)+bin2
        print(bin2)
    return bin2


### 16位二进制 原码 
def int2bin_16(n):   ## 输入参数为整数
    str1 = ''
    list1 = ['0' for i in range(16)]
    absn = abs(n)
    for i in range(15,0,-1):
        a = absn%2
        absn = absn//2
        list1[i] = str(a)
    # print(list1)  
    if n < 0:
        list1[0] = '1'
    str1=''.join(list1)      
    return str1


### 原码转补码
def yuan2bu(n):  # 输入为二进制原码字符串
    if n[0] == '0':
        return n
    else:
        str_bu = '1'
        for j in range(15,0,-1):
            if n[j]=='1':
                reverseindex = j
                break
        for k in range(1,reverseindex):
            if n[k]=='1':
                str_bu += '0'
            else:
                str_bu += '1'
        for m in range(reverseindex,16):
            str_bu += n[m]
    return str_bu


### 二进制转十六进制
def bin2hex(n):  #输入为二进制补码字符串
    str2 = ''
    dict1 = ['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F']
    list2 = []
    for j in range(0,16,4):
        sum1 = 0
        for k in range(4):
            sum1 = sum1 + int(n[j+k])*(2**(3-k))
        list2.append(dict1[sum1])
    str2=''.join(list2) 
    print(list2)
    return str2

    
while(1):
    num = input('Please input the num:')
    # print(type(num))
    flag_ifnum = True
    for p in range(len(num)):
        if p == 0:
            if (num[p] <='9' and num[p]>= '0') or (num[p] == '-') or (num[p] == '+'):
                continue
        if  num[p] <='9' and num[p] >= '0':
            continue
        else:
            flag_ifnum = False
    if not flag_ifnum:
        print('INPUTERROR')
    else:
        if abs(int(num))>=2**15:
            print('NODATA')
        else:
            bin_num_yuan = int2bin_16(int(num))
            bin_num_bu = yuan2bu(bin_num_yuan)
            # print(bin_num_bu)
            bin_yanzheng = bin(int(num))
            # print(bin_num_yuan)
            # print(bin_yanzheng)

            hex_num = bin2hex(bin_num_bu)
            # print(hex_num)
            hex_num_yanzheng = hex(int(num))
            # print(hex_num_yanzheng)
            print(bin_num_bu+','+hex_num)
            print('check_bin',bin_yanzheng)
            print('check_hex',hex_num_yanzheng)