将一串数字转换为二进制数

时间:2014-04-12 00:27:39

标签: c++ string binary

如果字符串是" 8123",我首先将字符串编号转换为整数形式8123,然后将此编号发送到将其转换为二进制的函数。我得到的数字和unsigned long long一样大,但是一旦它通过了,输出就错了。有没有办法通过查看每个数字转换为二进制。 即查看3,2,1和8以转换为二进制。

因此,而不是采取字符串" 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999"并将其转换为数字,有没有办法查看此字符串中的每个字符并将其转换为二进制文件?

非常感谢任何建议

2 个答案:

答案 0 :(得分:1)

伪代码:

string binary_string = ""
#an example
number = 81

while (number != 0)
    #append the string casted value of the remainder of (number / 2) 
    #to the front of binary_string
    binary_string = str(number % 2) + binary_string
    number = number / 2

e.g。 81:

binary_string = str(81%2)+ binary_string = str(1)+“”=“1”

number = 81/2 = 40

binary_string = str(40%2)+ binary_string = str(0)+“1”=“01”

number = 40/2 = 20

binary_string = str(20%2)+ binary_string = str(0)+“01”=“001”

number = 20/2 = 10

binary_string = str(10%2)+ binary_string = str(0)+“001”=“0001”

number = 10/2 = 5

binary_string = str(5%2)+ binary_string = str(1)+“0001”=“10001”

number = 5/2 = 2

binary_string = str(2%2)+ binary_string = str(0)+“10001”=“010001”

number = 2/2 = 1

binary_string = str(1%2)+ binary_string = str(1)+“010001”=“1010001”

81 - > “1010001”

答案 1 :(得分:1)

string dec2bin(string in) {
    for(size_t i = 0; i < in.length(); i++)
        in[i] -= '0';
    string out;
    while(in.length()) {
        out.insert(0, 1, '0' + (in[in.length()-1]&1));
        char overflow = 0;
        if(in[0]<=1) {
            overflow = 10;
            in.erase(0);
        }
        for(size_t i = 0; i<in.length(); i++) {
            in[i] += overflow;
            overflow = 10 * (in[i]&1);
            in[i] /= 2;
        }
    }
    return out;
}
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