Extract a Bit Field from a 32-bit Register

Code

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

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
    uint32_t regg=0;
    uint8_t j;
   for(int i=pos;i<pos+len;i++)
   {
    if(reg & (1<<i))
    {
        regg|=(1<<j);
    }
      j++;
   }
   return regg;
    
}

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;
}

Solving Approach