4. Set the Bit in an 8-bit Register

#include <stdio.h>
#include <stdint.h>

uint8_t set_bit(uint8_t reg, uint8_t pos) {
    // Your code here
    reg =( (reg & ~(1<<pos)) | (1<<pos) ); 
    return reg;
}

int main() {
    uint8_t reg, pos;
    scanf("%hhu %hhu", &reg, &pos);  // Accept register value and position
    uint8_t result = set_bit(reg, pos);
    printf("%u", result);         // Output the result as an integer
    return 0;
}

Step 1: Clear the bit at a given position by using this expression

reg = (reg & ~(1<<pos));

Step 2: Set the bit at a given position

reg = reg | (1<<pos);

Combining these two steps in one expression

reg =( (reg & ~(1<<pos)) | (1<<pos) );