21. Replace Bit Field in a 32-bit Register

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

void setBit(uint32_t* reg, uint8_t pos)
{
    *reg |= (1 << pos);
}

void clearBit(uint32_t* reg, uint8_t pos)
{
    *reg &= ~(1 << pos);
}

uint32_t replace_field(uint32_t reg, uint32_t val, uint8_t pos, uint8_t len) 
{
    for(uint8_t i = 0; i < len; i++)
    {
        if(val & (1 << (i)))
        {
            setBit(&reg, pos+i);
        }
        else
        {
            clearBit(&reg, pos+i);
        }
    }
    return reg;
}

int main() {
    uint32_t reg, val;
    uint8_t pos, len;
    scanf("%u %u %hhu %hhu", &reg, &val, &pos, &len);
    printf("%u", replace_field(reg, val, pos, len));
    return 0;
}