四则运算

// 按要求随机生成四则运算  王世强 2015/3/15
#include<iostream>
#include<stdlib.h>
#include<iomanip>
#include<time.h>
#include<stdio.h>
#include"math.h"
#define true 1
#define false 0
#define OPSETSIZE 7
#define random() (rand()%100000)
#include"string.h"
typedef int Status;
using namespace std;

unsigned char Prior[7][7] =
{ // 运算符优先级表
// '+' '-' '*' '/' '(' ')' '#'
/*'+'*/'>','>','<','<','<','>','>',
/*'-'*/'>','>','<','<','<','>','>',
/*'*'*/'>','>','>','>','<','>','>',
/*'/'*/'>','>','>','>','<','>','>',
/*'('*/'<','<','<','<','<','=',' ',
/*')'*/'>','>','>','>',' ','>','>',
/*'#'*/'<','<','<','<','<',' ','=',
};

typedef struct StackChar
{
char c;
struct StackChar *next;
}SC;       //StackChar类型的结点SC

typedef struct StackFloat
{
float f;
struct StackFloat *next;
}SF;       //StackFloat类型的结点SF

SC *Push(SC *s,char c)          //SC类型的指针Push，返回p
{
SC *p=(SC*)malloc(sizeof(SC));
p->c=c;
p->next=s;
return p;
}

SF *Push(SF *s,float f)        //SF类型的指针Push，返回p
{
SF *p=(SF*)malloc(sizeof(SF));
p->f=f;
p->next=s;
return p;
}

SC *Pop(SC *s)    //SC类型的指针Pop
{
SC *q=s;
s=s->next;
free(q);
return s;
}

SF *Pop(SF *s)      //SF类型的指针Pop
{
SF *q=s;
s=s->next;
free(q);
return s;
}

float Operate(float a,unsigned char theta, float b)      //计算函数Operate
{
switch(theta)
{
case '+': return a+b;
case '-': return a-b;
case '*': return a*b;
case '/': return a/b;
default : return 0;
}
}

char OPSET[OPSETSIZE]={'+','-','*','/','(',')','#'};

Status In(char Test,char *TestOp)
{
int Find=false;
for (int i=0; i< OPSETSIZE; i++)
{
if(Test == TestOp[i])
Find= true;
}
return Find;
}

Status ReturnOpOrd(char op,char *TestOp)
{
for(int i=0; i< OPSETSIZE; i++)
{
if (op == TestOp[i])
return i;
}
}

char precede(char Aop, char Bop)
{
return Prior[ReturnOpOrd(Aop,OPSET)][ReturnOpOrd(Bop,OPSET)];
}

float EvaluateExpression(char* MyExpression)
{
// 算术表达式求值的算符优先算法
// 设OPTR和OPND分别为运算符栈和运算数栈，OP为运算符集合
SC *OPTR=NULL;       // 运算符栈，字符元素
SF *OPND=NULL;       // 运算数栈，实数元素
char TempData[20];
float Data,a,b;
char theta,*c,Dr[]={'#','\0'};
OPTR=Push(OPTR,'#');
c=strcat(MyExpression,Dr);
strcpy(TempData,"\0");//字符串拷贝函数
while (*c!= '#' || OPTR->c!='#')
{
if (!In(*c, OPSET))
{
Dr[0]=*c;
strcat(TempData,Dr);           //字符串连接函数
c++;
if (In(*c, OPSET))
{
Data=atof(TempData);       //字符串转换函数(double)
OPND=Push(OPND, Data);
strcpy(TempData,"\0");
}
}
else    // 不是运算符则进栈
{
switch (precede(OPTR->c, *c))
{
case '<': // 栈顶元素优先级低
OPTR=Push(OPTR, *c);
c++;
break;
case '=': // 脱括号并接收下一字符
OPTR=Pop(OPTR);
c++;
break;
case '>': // 退栈并将运算结果入栈
theta=OPTR->c;OPTR=Pop(OPTR);
b=OPND->f;OPND=Pop(OPND);
a=OPND->f;OPND=Pop(OPND);
OPND=Push(OPND, Operate(a, theta, b));
break;
} //switch
}
} //while
return OPND->f;
} //EvaluateExpression

//符号生成
char create_symbol(int n)
{
int n1,j;
char symbol[1];
if(n==0)
{
n1=2;
}
else if(n=1)
{
n1=4;
}
j=random()%n1;
if(j==0) symbol[0]='+';
else if(j==1) symbol[0]='-';
else if(j==2) symbol[0]='*';
else symbol[0]='/';
return symbol[0];
}
//把数字转换成字符串型
string int_string(int number)
{
char str[200];
itoa(number,str,10);
string str_=str;
return str_;
}
//真分数合成一个字符串
string combination1(string str1,string str2,char k)
{
string equation;
equation='('+str1+k+str2+')';
return equation;
}
//新生成一个数
string create_num(int proper_fs,int range)
{
int num,num1,num2,fs;
string str_num,str_num1,str_num2;
num=random()%range+1;
str_num=int_string(num);
if(proper_fs==1)
{
fs=random()%3;
if(fs==1)//判断是否生成真分数
{
for(;;)
{
num1=random()%range+1;
num2=random()%range+1;
if(num1<num2) break;
}
str_num1=int_string(num1);
str_num2=int_string(num2);
str_num=combination1(str_num1,str_num2,'/');
}
}
return str_num;
}
//运算式转换成一个字符串
string combination(string str1,string str2,char k)
{
string equation;
equation=str1+k+str2;
return equation;
}

//得出正确答案
float get_ans(string str)
{
int len;
float ans;
len=str.length();
char num[len];
for(int j=0;j<len;j++)
{
num[j]=str[j];
}
//用堆栈解决。。。
ans=EvaluateExpression(num);
return ans;
}
//主函数
int main()
{
srand((int)time(NULL));  //设置时间种子 ，使得程序每次运行的结果都不同
int num1,num2,num3,num4,count,n,change,amount,shuchu,range,j,repeat=0,bracket,proper_fs;
string str_num1,str_num2,temp;
float Answer,InputAns;
cout<<"有无乘除法？1有，0没有："<<endl;
cin>>n;
cout<<"是否有括号？1有，0没有："<<endl;
cin>>bracket;
cout<<"是否有真分数？1有，0没有："<<endl;
cin>>proper_fs;
cout<<"请输入数字范围："<<endl;
cin>>range;
cout<<"请输入出题数量："<<endl;
cin>>amount;
string Equation[amount];
char symbol;
cout<<amount<<"道四则运算题如下："<<endl;
for(int i=0;i<amount;i++)
{
count=random()%3+2;
str_num1=create_num(proper_fs,range);
str_num2=create_num(proper_fs,range);
symbol=create_symbol(n);
Equation[i]=combination(str_num1,str_num2,symbol);
if(count>2)
{
for(count;count>2;count--)
{
symbol=create_symbol(n);
str_num1=Equation[i];
if(bracket==1)
{
change=random()%3;
if(change==0)
{
str_num1='('+str_num1+')';
}
}
symbol=create_symbol(n);
str_num2=create_num(proper_fs,range);
change=random()%2;
if(change==0)
{
temp=str_num1;
str_num1=str_num2;
str_num2=temp;
}
Equation[i]=combination(str_num1,str_num2,symbol);
}
}
//判断是否重复
for(j=0;j<i;j++)
{
if(Equation[j]==Equation[i])
{
i=i-1;
repeat=1;
break;
}
}
if(repeat!=1)//若不重复，则输出
{
cout<<Equation[i]<<"=";
//判断结果是否正确
cin>>InputAns;
Answer=get_ans(Equation[i]);
Answer*=100;
int temp=(int)Answer;
Answer=((double)temp)/100.00;
if(InputAns==Answer)
{
cout<<"回答正确！";
}
else
{
cout<<"回答错误！正确答案为";
cout<<setprecision(2)<<fixed<<Answer;
}
cout<<endl;
}
}
}