/*求解简单的五则运算表达式*/ #include
     
      int main(void){	double num1,num2;	char op;	printf("Type in an expression:");     /*提示输入一个表达式*/ 	scanf("%lf%c%lf",&num1,&op,&num2);    /*输入表达式*/	 	if(op=='+')                           /*判断运算符是否为’+‘*/ 		printf("=%.2f\n",num1+num2);	else if(op=='-')                      /*判断运算符是否为’-‘*/ 		printf("=%.2f\n",num1-num2);	else if(op=='*')                      /*判断运算符是否为’*‘*/ 		printf("=%.2f\n",num1*num2);	else if(op=='/')                       /*判断运算符是否为’/'*/ 		printf("=%.2f\n",num1/num2);		else		printf("Unknown operator\n");   /*运算符输入错误*/	return 0;}