18. Set Multiple Bits in 8-bit Register

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

uint8_t set_range(uint8_t reg, uint8_t start, uint8_t end) {
    uint16_t temp =(( end - start ) + 1 );
    uint16_t val = (pow(2,temp)) - 1;
    reg &= ~(val << start);
    reg |= (val << start);
    return reg;
}

int main() {
    uint8_t reg, start, end;
    scanf("%hhu %hhu %hhu", &reg, &start, &end);
    printf("%u", set_range(reg, start, end));
    return 0;
}