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| #include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<iostream>
using namespace std;
template <class T>
class mystack{
T sta[500];
int s_top;
public:
mystack(){
s_top=0;
}
void push(T n){
if(s_top>=499)
printf("栈满了，进栈失败！\n");
else
sta[++s_top]=n;
}
void pop(){
if(s_top==0)
{printf("栈为空，不能出栈。\n");exit(1);}
else
--s_top;
}
T top(){
return sta[s_top];
}
void clear(){
s_top=0;
}
bool empty(){
return s_top==0;
}
int size(){
return s_top;
}
void printstack(){
int i;
for(i=1;i<=s_top;i++)
cout<<sta[i]<<" ";
printf(" 大小是:%d\n",s_top);
}
};
mystack<double> ovs;
mystack<char> ops;
char s[1005];
int comp(char);
double calculate(double ,char ,double);
int main()
{
int N;
int i,j;
double num1,num2;
char op;
char w[100];
while(printf("请输入算式(输入\"exit\"退出):"),~scanf("%s",s),strcmp(s,"exit"))
{
ops.push('#');
for(i=0;s[i]!='=';)
{
printf("当前处理:");
if(s[i]>='0' && s[i]<='9')
{
j=0;
w[j++]=s[i++];
while((s[i]>='0' && s[i]<='9') || s[i]=='.')
{
w[j++]=s[i++];
}
w[j]='\0';
printf("%s\n",w);
ovs.push(atof(w));
}
else
{
if(comp(ops.top())<comp(s[i]) || s[i]=='(')
{
printf("%c\n",s[i]);
ops.push(s[i]);
i++;
}
else if(ops.top()=='(' && s[i]==')')
{
printf("%c\n",s[i]);
ops.pop();
i++;
}
else
{
num2=ovs.top(); ovs.pop();
num1=ovs.top(); ovs.pop();
op=ops.top(); ops.pop();
cout<<num1<<" "<<op<<" "<<num2<<endl;
ovs.push(calculate(num1,op,num2));
}
}
printf("运算符当前栈为:");
ops.printstack();
printf("操作数当前栈为:");
ovs.printstack();
printf("\n");
}
while(ovs.size()!=1)
{
printf("当前处理:");
num2=ovs.top(); ovs.pop();
num1=ovs.top(); ovs.pop();
op=ops.top(); ops.pop();
printf("%lf%c%lf\n",num1,op,num2);
ovs.push(calculate(num1,op,num2));
}
printf("\n\n运算结果:%s%.2lf\n",s,ovs.top());
ovs.clear();
ops.clear();
}
return 0;
}
int comp(char op)
{
int t;
switch(op)
{
case '*':
case '/':t=3;break;
case '+':
case '-':t=2;break;
case '(':
case ')':t=1;break;
case '#':t=0;break;
default :printf("%c_error!\n",op);exit(1);
}
return t;
}
double calculate(double num1,char op,double num2)
{
double ans;
switch(op)
{
case '*':ans=num1*num2;break;
case '/':ans=num1/num2;break;
case '+':ans=num1+num2;break;
case '-':ans=num1-num2;break;
default :printf("%c_error!\n",op);exit(1);
}
return ans;
}
|
