20. Clear Specific Bits in a 32-bit Register

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

uint32_t clear_bits(uint32_t reg, uint8_t pos, uint8_t len)
{
    uint32_t mask=0x00; //initially creating mask with 0.
    mask=((1<<len)-1); //getting mask of required length.
    mask=mask<<pos;    //shifting the mask to required position.
    return (reg & (~(mask)));
}

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