Clear Specific Bits in a 32-bit Register

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

uint32_t clear_bits(uint32_t reg, uint8_t pos, uint8_t len) {
    // Your code here

    uint8_t mask = 0; 

    for (int i = 0 ; i < len ; i++) {
        mask += pow(2 , i);
    }

    reg &= ~(mask << pos); 

    return reg;
}

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;
}