虫食い算

#include <stdio.h>

#define N 9

double check(void);
void printResult(void);
void warm(int k);

int a[N];
int f[10];

int main(void)
{
        warm(0);
        return 0;
}

double check(void){
int x, y, z, chk;

        chk = (a[3] * 10 + a[4]) % a[5];
        x = a[0] * 10 + a[1] - a[2];
        y = (a[3] * 10 + a[4]) / a[5];
        z = a[6] + a[7] * a[8];

        return chk == 0 && x == y && y == z;
}

void printResult(void)
{
        printf("%d%d-%d=%d%d÷%d=%d+%d×%d\n", a[0], a[1], a[2], a[3], a[4], a[5], a
[6], a[7], a[8]);
}

void warm(int k)
{
        int i;

        if (k == N) {
                if (check()) printResult();
        }
        else {
                for (i = 1; i <= 9; i++) {
                        if (f[i]) continue;
                        a[k] = i;
                        f[i] = 1;
                        warm(k + 1);
                        f[i] = 0;
                }
        }
}