19. Extract a Bit Field from a 32-bit Register

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

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
    // Your code here 
    if (len == 0) {
        return 0;
    }
    
    // Safety check: Prevent undefined behavior from (1U << 32)
    if (len >= 32) {
        return reg; 
    }
    uint32_t shifted_reg = reg >> pos;

    uint32_t mask=(1u<<len)-1u ;
      
   return shifted_reg & mask;
    
    
}

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