Validate Configuration Register Layout

Code

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    unsigned short reg;
    reg=cfg->reg;
    unsigned short r=reg;
    if(reg&0x1==0)return 0;
    else if(reg>>2&0x1==1 && r>>3&0x1==1)return 0;
    else if(reg>>4 & 0xFFFF!=0)return 0;
    else return true;
}

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

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

    return 0;
}

Solving Approach