C 移位的最高有效位为1

我正在写一个C函数，它从用户那里获取一个数字并将其转换成二进制输出。首先，代码如下：

void Convert_Number_To_Binary(const int num,char *binary) {
    double remainder = num;

    //Start from binary[0] and check if num is divisible by 2^ith power by shifting
    for(int i = 0; i < 33; i++) {
        int shift = num >> i; //shift the current bit value of remainder i bits
        printf("i: %d, %d \n", i,  (shift) );

        //If shift is greater than 0, then remainder is divisible by 2^i
        if( (shift & 1) > 0) {
                binary[32-i] = '1';
        }
        else
                binary[32-i] = '0';
        //printf("i:%d, 32-i:%d\n", i, (32-i));
    }

    //printf("%c, %c", binary[0], binary[31]);

    binary[33] = '\0';
}

对于偶数，前导的“1”不会出现：

num = 16    binary = 000000000000000000000000000010000

---

我在远程32位linux机器上运行此操作，这可能是原因吗？

您应该首先将

int

强制转换为

未签名int

，这将强制MSB填充0

大概是这样的：

unsigned int shift = (unsigned int)num >> i;

---

您正在创建一个33位的二进制字符串，而不是32位：

for(int i = 0; i < 33; i++) {
    int shift = num >> i; //shift the current bit value of remainder i bits

for(int i = 0; i < 33; i++) {
    int shift = num >> i; //shift the current bit value of remainder i bits

void Convert_Number_To_Binary(const int num,char *binary) {
    //Start from binary[0] and check if num is divisible by 2^ith power by shifting
    for(int i = 0; i < 32; i++) {
        int shift = num >> i; //shift the current bit value of remainder i bits
        printf("i: %d, %d \n", i,  (shift) );

        //If shift is greater than 0, then remainder is divisible by 2^i
        if( (shift & 1) > 0) {
                binary[32-i-1] = '1';
        }
        else
                binary[32-i-1] = '0';
        //printf("i:%d, 32-i-1:%d\n", i, (32-i-1));
    }

    //printf("%c, %c", binary[0], binary[31]);

    binary[32] = '\0';
}