Question

嗨，我对c很新，但对于我写的程序，我需要将二进制字符串转换为十进制数字。这是我目前的代码：

int BinaryToInt(char *binaryString)
{
    int decimal = 0;
    int len = strlen(binaryString);
    for(int i = 0; i < len; i++)
    {

        if(binaryString[i] == '1')
            decimal += 2^((len - 1) - i);
        printf("i is %i and dec is %i and the char is %c but the length is %i\n", i, decimal, binaryString[i], len);
    }
    return decimal;
}

int main(int argc, char **argv)
{
    printf("%i", BinaryToInt("10000000"));
}

这是输出：

i is 0 and dec is 5 and the char is 1 but the length is 8
i is 1 and dec is 5 and the char is 0 but the length is 8
i is 2 and dec is 5 and the char is 0 but the length is 8
i is 3 and dec is 5 and the char is 0 but the length is 8
i is 4 and dec is 5 and the char is 0 but the length is 8
i is 5 and dec is 5 and the char is 0 but the length is 8
i is 6 and dec is 5 and the char is 0 but the length is 8
i is 7 and dec is 5 and the char is 0 but the length is 8
5

我很困惑为什么这不起作用，非常感谢所有的帮助。提前谢谢！

Ps：我已经习惯了java，所以目前C只是让我哭泣

Answer 1

^运算符不用于取幂，而是按位XOR运算符。

如果您想将数字提高到2的幂，请使用左移位运算符<<将值1移动到相关指数。

decimal += 1 << ((len - 1) - i);

Answer 2

技巧与任何数字基数相同：对于每个输入数字，将累加器乘以数字基数并添加数字。

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

int BinaryToInt(char *binaryString)
{
    int decimal = 0;
    int len = strlen(binaryString);
    for(int i = 0; i < len; i++) {
        decimal = decimal * 2 + binaryString[i] - '0';
    }
    return decimal;
}

int main(void)
{
    printf("%d", BinaryToInt("10000000"));
    return 0;
}

节目输出：

c中的二进制到十进制算法给出了奇怪的结果

2 个答案: