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) {
    // Nếu len = 32, tức là set toàn bộ bit -> return 0xFFFFFFFF
    if (len == 32) return 0xFFFFFFFF; 
    
    uint32_t mask = (1U << len) - 1;
    return reg | (mask << pos);
}

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