#include <stdio.h>
#include <stddef.h>
/*
* Converts an unsigned integer to a binary string with leading zeros.
* - num: The integer value to convert.
* - bits: The exact bit width (e.g., 8, 16, 32) determining the leading zeros.
* - buffer: Pre-allocated character array to hold the resulting string.
* - buffer_size: Size of the buffer (must be at least bits + 1 for the null terminator).
*/
void int_to_binary(unsigned int num, int bits, char *buffer, size_t buffer_size) {
// Ensure the buffer is large enough to hold the bits plus the null terminator
if (buffer_size <= (size_t)bits) {
return;
}
// Null-terminate the string at the end of the specified bit width
buffer[bits] = '\0';
// Fill the buffer from right to left (least significant bit to most significant bit)
for (int i = bits - 1; i >= 0; i--) {
// Extract the lowest bit and convert it to its character representation ('0' or '1')
buffer[i] = (num & 1) ? '1' : '0';
// Shift the number right by 1 bit to inspect the next position
num >>= 1;
}
}
int (main)(void) {
// Define the data provided
unsigned int num = 153;
// 1. Convert to an 8-bit binary representation (153 fits within 8 bits: 0 to 255)
const int bits_8 = 8;
char bin_str_8[9]; // 8 bits + 1 for null terminator '\0'
int_to_binary(num, bits_8, bin_str_8, sizeof(bin_str_8));
// 2. Convert to a 16-bit binary representation to demonstrate padding
const int bits_16 = 16;
char bin_str_16[17]; // 16 bits + 1 for null terminator '\0'
int_to_binary(num, bits_16, bin_str_16, sizeof(bin_str_16));
// Output the results
printf("Original Integer: %u\n", num);
printf("Binary (8-bit) : %s\n", bin_str_8);
printf("Binary (16-bit) : %s\n", bin_str_16);
return 0;
}
/*
run:
Original Integer: 153
Binary (8-bit) : 10011001
Binary (16-bit) : 0000000010011001
*/
