#include <string.h>
#include <stdlib.h>
#include <time.h>
void menu() {
char sl;
int i,an,a,b,n = 10;
do {
printf("\t************************************************************\n");
printf("\t* 加法(A) 減法(S) 乘法(M) 除法(D) 退出(E) *\n");
printf("\t************************************************************\n");
printf("\n請選擇 : ");
fflush(stdin);
scanf("%c",&sl);
srand((unsigned)time(NULL));
switch(sl) {
case 'a' :
case 'A' :
for(i = 0; i < n; ++i) {
do {
a = rand()%100;
b = rand()%100;
}while(a + b >= 100);
do {
printf("%d＋%d＝",a,b);
scanf("%d",&an);
}while(an != a + b);
}
break;
case 's' :
case 'S' :
for(i = 0; i < n; ++i) {
do {
a = rand()%100;
b = rand()%100;
}while(a - b < 0);
do {
printf("%d－%d＝",a,b);
scanf("%d",&an);
}while(an != a - b);
}
break;
case 'm' :
case 'M' :
for(i = 0; i < n; ++i) {
do {
a = rand()%100;
b = rand()%100;
}while(a * b >= 100);
do {
printf("%d×%d＝",a,b);
scanf("%d",&an);
}while(an != a * b);
}
break;
case 'd' :
case 'D' :
for(i = 0; i < n; ++i) {
do {
a = rand()%100;
b = rand()%100;
}while((a < b) || !b || (a % b));
do {
printf("%d÷%d＝",a,b);
scanf("%d",&an);
}while(an != a / b);
}
break;
case 'e' :
case 'E' : break;
}
}while(sl != 'e' && sl != 'E');
}
int main() {
char s[20],password[] = "12345";
do {
printf("請輸入密碼(Ctrl + C 退出) : ");
gets(s);
}while(strcmp(s,password));
menu();
return 0;
}