c语言代码的解释？

Question

请问一下这段代码是数据结构的，谁能看得懂能给我解释一下？

#include"stdio.h"

#include"stdlib.h"

#include"string.h"

#include"math.h"

#define true 1

#define false 0

#define OPSETSIZE 8

typedef int Status;

 

unsigned char Prior[8][8] =

{ // 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;

    case '^': return pow(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

 

int main(void)

{

    char s[128];

    puts("请输入表达式:");

    gets(s);

    puts("该表达式的值为:");

    printf("%s\b=%g\n",s,EvaluateExpression(s));

    system("pause");

    return 0;}  

Answer 1

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