我可以用printf打印十六进制或八进制数字。是否有格式标签打印为二进制或任意基数?
我正在运行gcc。
printf("%d %x %o\n", 10, 10, 10); //prints "10 A 12\n"
printf("%b\n", 10); // prints "%b\n"
我可以用printf打印十六进制或八进制数字。是否有格式标签打印为二进制或任意基数?
我正在运行gcc。
printf("%d %x %o\n", 10, 10, 10); //prints "10 A 12\n"
printf("%b\n", 10); // prints "%b\n"
当前回答
至于我,我为此编写了一些通用代码
#include<stdio.h>
void int2bin(int n, int* bin, int* bin_size, const int bits);
int main()
{
char ch;
ch = 'A';
int binary[32];
int binary_size = 0;
int2bin(1324, binary, &binary_size, 32);
for (int i = 0; i < 32; i++)
{
printf("%d ", binary[i]);
}
return 0;
}
void int2bin(int n, int* bin,int *bin_size,const int bits)
{
int i = 0;
int temp[64];
for (int j = 0; j < 64; j++)
{
temp[j] = 0;
}
for (int l = 0; l < bits; l++)
{
bin[l] = 0;
}
while (n > 0)
{
temp[i] = n % 2;
n = n / 2;
i++;
}
*bin_size = i;
//reverse modulus values
for (int k = 0; k < *bin_size; k++)
{
bin[bits-*bin_size+k] = temp[*bin_size - 1 - k];
}
}
其他回答
// m specifies how many of the low bits are shown.
// Replace m with sizeof(n) below for all bits and
// remove it from the parameter list if you like.
void print_binary(unsigned long n, unsigned long m) {
static char show[3] = "01";
unsigned long mask = 1ULL << (m-1);
while(mask) {
putchar(show[!!(n&mask)]); mask >>= 1;
}
putchar('\n');
}
下面是paniq解决方案的一个小变种,它使用模板来允许打印32位和64位整数:
template<class T>
inline std::string format_binary(T x)
{
char b[sizeof(T)*8+1] = {0};
for (size_t z = 0; z < sizeof(T)*8; z++)
b[sizeof(T)*8-1-z] = ((x>>z) & 0x1) ? '1' : '0';
return std::string(b);
}
并且可以这样使用:
unsigned int value32 = 0x1e127ad;
printf( " 0x%x: %s\n", value32, format_binary(value32).c_str() );
unsigned long long value64 = 0x2e0b04ce0;
printf( "0x%llx: %s\n", value64, format_binary(value64).c_str() );
结果如下:
0x1e127ad: 00000001111000010010011110101101
0x2e0b04ce0: 0000000000000000000000000000001011100000101100000100110011100000
使用标准库将任何整型转换为二进制字符串表示的语句泛型:
#include <bitset>
MyIntegralType num = 10;
print("%s\n",
std::bitset<sizeof(num) * 8>(num).to_string().insert(0, "0b").c_str()
); // prints "0b1010\n"
或者只是: std::cout << std::bitset<sizeof(num) * 8>(num);
你可以使用一个小表格来提高速度。类似的技术在嵌入式世界中也很有用,例如,反转一个字节:
const char *bit_rep[16] = {
[ 0] = "0000", [ 1] = "0001", [ 2] = "0010", [ 3] = "0011",
[ 4] = "0100", [ 5] = "0101", [ 6] = "0110", [ 7] = "0111",
[ 8] = "1000", [ 9] = "1001", [10] = "1010", [11] = "1011",
[12] = "1100", [13] = "1101", [14] = "1110", [15] = "1111",
};
void print_byte(uint8_t byte)
{
printf("%s%s", bit_rep[byte >> 4], bit_rep[byte & 0x0F]);
}
1我主要指的是嵌入式应用程序,其中优化器不是那么激进,速度差异是可见的。
简单,经过测试,适用于任何无符号整数类型。没有头痛。
#include <stdint.h>
#include <stdio.h>
// Prints the binary representation of any unsigned integer
// When running, pass 1 to first_call
void printf_binary(unsigned int number, int first_call)
{
if (first_call)
{
printf("The binary representation of %d is [", number);
}
if (number >> 1)
{
printf_binary(number >> 1, 0);
putc((number & 1) ? '1' : '0', stdout);
}
else
{
putc((number & 1) ? '1' : '0', stdout);
}
if (first_call)
{
printf("]\n");
}
}