Question

用C语言实现计算器，要有按键功能！（+-*/即可）

用C语言

Answer 1

#include<stdio.h>
#include<malloc.h>
#include<iostream.h>

struct node
{
int date;
struct node *next;
};
typedef struct node *link;
link number=NULL;
link symble=NULL;
//把数据放入栈中//
link push(link stack ,int num,int k)
{ link newnode;
newnode=(link)malloc(sizeof(struct node));
if(newnode==NULL)
cout<<"out of space"<<endl;
else
{ if(k>=0 && k<=9)//判断前一个字符是否为数字
{
stack->date=stack->date*10+num;
return stack;
}
else
{
newnode->date=num;
newnode->next=stack;
stack=newnode;
return stack;

}
}
}

//从栈上取出数据//
link pull(link stack,int *num)
{
link top;//去栈顶元素
if(stack!=NULL)
{
top=stack;
stack=stack->next;
*num=top->date;
free(top);
return stack;

}
else
*num=0;

}
//判断栈是否为空
int empty(link stack)
{
if(stack==NULL)
return 1;
else
return 0;

}
//判断是否为运算符
int is_symble(char ch)
{
switch(ch)
{ case '(':
case ')':
case '+':
case '-':
case '*':
case '/':
return 1;
default:
return 0;
}

}
// 判断运算符的优先级
int priority(char ch)
{
switch(ch)
{ case '(':
return 1;
case '+':
case '-':return 2;
case '*':
case '/': return 3;//'+','-'的优先级小于'*','/'
default:return 0;
}

}
//计算两个操作数的值
int tuo_result(int m,int num1,int num2 )
{ switch(m)
{ case '+':
return(num2 + num1);
case '-':
return (num2-num1);
case '*':
return(num2 * num1);
case '/':
return(num2 / num1);
}

}

//主函数
void main ()
{
char expression[50];//存放表达式
int position=0;//表达式的位置
int sym=0;//运算符
int num1=0;//后操作数
int num2=0;//前操作数
int sum=0;//运算结果
cout<<"请输入表达式："<<endl;
gets(expression);
while(expression[position]!='\0' && expression[position]!='\n')
{ if(is_symble(expression[position]))//判断运算符
{
if(expression[position]=='(')
symble=push(symble,expression[position],-1);
else if(expression[position]==')')
{ while(symble->date!='(')
{ number=pull(number,&num1);
number=pull(number,&num2);
symble=pull(symble,&sym);
number=push(number,tuo_result(sym,num1,num2),-1);
}
//if(symble->date='(')symble=pull(symble,&sym);
symble=pull(symble,&sym);

}

else if(!empty(symble))//判断放运算符的栈是否为空

{ if(priority(expression[position]) <= priority(symble->date) &&
!empty(symble))
{
//取出一个运算符和两个操作数
number=pull(number,&num1);
number=pull(number,&num2);
symble=pull(symble,&sym);
number=push(number,tuo_result(sym,num1,num2),-1);
//cout<<tuo_result(sym,num1,num2)<<endl;
//把运算符放在栈里
//symble=push(symble,expression[position],-1);
}
symble=push(symble,expression[position],-1);
}

//把运算符放在栈里
else
symble=push(symble,expression[position],-1);

}
else if(!is_symble(expression[position]))//把操作数放在栈里
number=push(number,expression[position]-48,expression[position-1]-48);
//cout<<expression[position]<<endl;

position++;
}

//取出运算符栈的运算符
while(!empty(symble))
{ //cout<<symble->date<<endl;

symble=pull(symble,&sym);
if(!empty(symble))//判断是否为空
{
if(sym=='+' && symble->date=='-' )//判断符号问题 ，2-2*3+5=1不然就是-1
sym='-';
}
number=pull(number,&num1);
number=pull(number,&num2);

//cout<<num1<<" "<<num2<<endl;
//计算的结果放在栈中
number=push(number, tuo_result(sym,num1,num2),-1);
//cout<<number->date<<endl;

}
//取出运算结果
number=pull(number,&sum);
cout<<expression<<"="<<sum<<endl;

}

Answer 2

//实现计算机功能的程序 a program which can work the functions as a computer.
#include <stdio.h>//头文件
#include <conio.h>
void menu();//声明部分
void add();
void sub();
void mul();
void div();
void remain();
void add_n_to_m();
void factor();
main()
{
int i;
while(1)
{
system("cls");//清屏功能
menu();
printf("choose function:");
scanf("%d",&i);
switch(i)
{
case 1:add();getch();break;//调用部分
case 2:sub();getch();break;
case 3:mul();getch();break;
case 4:div();getch();break;
case 5:remain();getch();break;
case 6:add_n_to_m();getch();break;
case 7:factor();getch();break;
case 8: exit(0);break;
}
}
}
//以下是自己定义的函数
void menu()//菜单
{
printf("+====my counter===+\n");
printf("+功能如下: +\n");
printf("+ 1.加法 +\n");
printf("+ 2.减法 +\n");
printf("+ 3.乘法 +\n");
printf("+ 4.除法 +\n");
printf("+ 5.求余 +\n");
printf("+ 6.从n到m的和+\n");
printf("+ 7.阶乘 +\n");
printf("+ 8.退出 +\n");
printf("+=================+\n");
}
void add()//加法运算
{
double a,b;
printf("input two numbers:");
scanf("%lf%lf",&a,&b);
printf("%lf+%lf=%lf\n",a,b,a+b);
}
void sub()//减法运算
{
double a,b;
printf("input two numbers:");
scanf("%lf%lf",&a,&b);
printf("%lf-%lf=%lf\n",a,b,a-b);
}
void mul()//乘法运算
{
double a,b;
printf("input two numbers:");
scanf("%lf%lf",&a,&b);
printf("%lf*%lf=%lf\n",a,b,a*b);
}
void div()//除法运算
{
double a,b;
printf("input two numbers:");
scanf("%lf%lf",&a,&b);
if(b==0)//被除数不能为0
printf("error\n");
else
printf("%lf/%lf=%lf\n",a,b,a/b);
}
void remain()//求余运算
{
int a,b;
printf("input two numbers:");
scanf("%d%d",&a,&b);
if(b==0)//被除数不能为0
printf("error\n");
else
printf("%d%%%d=%d\n",a,b,a%b);
}
void add_n_to_m()//累加
{
int m,n,i=0,s=0;
printf("input n and m:");
scanf("%d%d",&n,&m);
if(n>m) printf("error.\n");//条件限制
else
{
for(i=n;i<=m;i++)
s+=i;
printf("%d+...+%d=%d\n",n,m,s);
}
}
void factor()//阶乘
{
int n,i,s;
printf("input a number:");
scanf("%d",&n);
if(n<=0) printf("error.\n");//条件限制
else
{
for(i=1,s=1;i<=n;i++)
s*=i;
printf("%d!=%d\n",n,s);
}