c语言程序设计，求解

#define N 6
int main(void){
    char a[N][N], i, j, k;
    for (k = 1, i = 0; i<6; i++)
        if (i & 1)
            for (j = 5; j >= 0; a[i][j--] = k++);
        else
            for (j = 0; j<6; a[i][j++] = k++);
    for (i = 0; i<6; i++){
        for (j = 0; j<6; printf("%3d", a[i][j++]));
        printf("\n");
    }
    system("pause");
    return 0;
}