Set Specific Bits in a 32-bit Register

Code

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

uint32_t set_bits(uint32_t reg, uint8_t pos, uint8_t len) {
    uint32_t mask = ((1u << len) - 1) << pos;
    // ((1 << len) - 1): tao mat na mask trc 
    // ((1 << len) - 1) << pos: sau do moi dich den vi tri can thay doi
    return reg | mask;
    // VD len = 3
    // (1 << len): 0000 1000 
    // ((1 << len) - 1): 0000 0111
    // sau do dich den pos va cong vao nhu bth vd pos = 4 0000 0111--> 0111 0000
}

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

Solving Approach