Simple C RPS game

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main() {
    srand(time(NULL));                              /* initiating random number generator with seed time */
    short choice_computer = 1 + rand() % (3);       /* generating a random number between 1 - 3 */
    short choice_user;

    printf("1 = rock; 2 = paper; 3 = scissors\n");
    printf("Choose wisely: ");

    scanf("%hi", &choice_user);

    printf("\nComputer chose option %hi\n", choice_computer);
    printf("You chose option %hi\n", choice_user);

    if(choice_user < 1 || choice_user > 3){         /* checking if user input is valid */
        printf("\nInvalid choice!\n");
        return 1;
    }

    if(choice_computer - choice_user == 0){         /* calculating the outcome */
        printf("\nIt's a draw!\n");
    }else if(choice_computer - choice_user == 1 || choice_computer - choice_user == -2){
        printf("\nComputer wins!\n");
    }else{
        printf("\nYou win!\n");
    }

    return 0;
}