猜数字小游戏 v1

#include <stdio.h>
#define SIZE 4


/* function prototype */
void introduction(void); /* game introduction */
void judgement(int[], int[]);

int main(void){
    int goal[SIZE] = { 1, 2, 3, 4 };
    int guess[SIZE];

    introduction(); /* title: illustrate how to play the game */


    if ( getchar() == 'y' ){
        printf("Okey! Let`s start\n");

        int input_num;
        while (scanf_s("%d", &input_num) != EOF){
            /* Use the every bits of four digits, assigned
            to the array guess`s element, respectively */
            guess[0] = input_num / 1000;
            guess[1] = (input_num - guess[0] * 1000) / 100;
            guess[2] = (input_num - (guess[0] * 1000 + guess[1] * 100)) / 10;
            guess[3] = input_num - (guess[0] * 1000 + guess[1] * 100 + guess[2] * 10);
            /* print the number just input */
            printf("%d%d%d%d", guess[0], guess[1], guess[2], guess[3]);
            /* call the judgement function */
            judgement(goal, guess);
        }
    }
    else{
        printf("Okey! See you next time, Bye!\n");
    }

    return 0;
}

/* only print the illustrate of the game on screen */
void introduction(void){
     printf("*********************   GAME INTRODUCTION   *********************\n\n"
         "There is a number composed by 4 figures(0~9), and without repetition.\n"
         "Guess the number. If the figure and the position all correct, then\n"
         "output A, if the figure is correct but the positon is incorrect,\n"
         "then output B, the goal is 4A0B. OKey!! Come on baby!!!\n"
         "Are you ready?(y/n):");
}

/* judge the goal number and the guess number matching or not */
void judgement(int judge_goal[SIZE], int judge_guess[SIZE]){
    int a = 0, b = 0;/* counter */
    /* count the number and the position all correct */
    for (int i = 0; i < SIZE; i++){
        if (judge_goal[i] == judge_guess[i]){
            a++;
        }
        /* count the number correct (if the number matching, then b+1)*/
        for (int j = 0; j < SIZE; j++){
            if (judge_goal[i] == judge_guess[j])
                b++;
        }
    }
    /* b include a, so b-a */
    b = b - a;
    printf("------%d数字、位置都正确; %d数字正确、但位置不正确\n", a, b);
}