Validate Configuration Register Layout

Code

#include <stdio.h>

typedef struct {
    union {
        unsigned short reg;
        struct {
            unsigned en : 1;
            unsigned mode : 1;
            unsigned priority : 2;
            unsigned reserved : 12;
        } bitfield;
    };
    
    
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    if (cfg->bitfield.en == 0) return 0;

    if (cfg->bitfield.priority == 3) return 0;

    if (cfg->bitfield.reserved != 0) return 0;
    
    return 1;
}

int main() {
    ConfigRegister cfg;
    scanf("%hx", &cfg.reg);

    int result = validate_config(&cfg);
    printf("%d", result);

    return 0;
}

Solving Approach