#include <stdio.h>
int main() {
char operator;
double a, b, result;
printf("********************************\n");
printf(" 欢迎使用小型计算器\n");
printf(" 设计人:纪佳伟\n");
printf("********************************\n");
printf(" 1.加法运算\n");
printf(" 2.减法运算\n");
printf(" 3.乘法运算\n");
printf(" 4.除法运算\n");
printf(" 5.退出\n");
printf("********************************\n");
printf("请选择: ");
scanf(" %c", &operator);
printf("请输入两个数: ");
scanf("%lf %lf", &a, &b);
switch (operator) {
case '1':
result = a + b;
break;
case '2':
result = a - b;
break;
case '3':
result = a * b;
break;
case '4':
if (b != 0) {
result = a / b;
} else {
printf("Error: Division by zero is not allowed.\n");
return 1;
}
break;
default:
printf("Error: Invalid operator.\n");
return 1;
}
printf("两个数相加是: %.2lf\n", result);
return 0;
}