中缀表达式转换成后缀表达式

/* solution of convertion of infix to postfix */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>



struct StackRecord

{

    char Operator[32];

    int TopIndex;

    int Capacity;

};



typedef struct StackRecord * Stack;



Stack CreateStack()

{

    Stack S = malloc(sizeof(struct StackRecord));

    S->TopIndex = -1;

    S->Capacity = 32;

}

inline int IsEmpty(Stack S){return S->TopIndex == -1;}

inline int IsFull(Stack S){return S->TopIndex == 31;}

void Push(Stack S,char Operator)

{

    // assuming S is not NULL, hha

    S->Operator[++S->TopIndex] = Operator;

}

char Pop(Stack S)

{

    if(IsEmpty(S)) return 0;

    return S->Operator[S->TopIndex--];

}

char Top(Stack S)

{

    if(IsEmpty(S)) return 0;

    return S->Operator[S->TopIndex];

}

int GetOperatorClass(char Operator)

{

    switch(Operator)

    {

    case '+': case '-':

        return 0;

    case '*': case '/':

        return 1;

    case '^':

        return 2;

    case '(':

        return 10;

    default:

        return -1;

    }

}

int IsOperator(char c)

{

    switch(c)

    {

    case '+':case '-':case '*':case '/':case '(':case ')':case '^':

        return 1;

    default:

        return 0;

    }

}

void PrintStack(Stack S)

{

    int i = 0;

    printf("Current Stack: ");

    for(; i <= S->TopIndex; ++i)

        printf("%c ", S->Operator[i]);

    printf("\n");

}



int main()

{

    char *infix = "a+b*c^h^i+(d*e+f)*g";

    char postfix[128] = "\0";

    int len = strlen(infix);

    int i = 0;

    Stack S = CreateStack();

    char top;

    int j = 0;

    char curr;

    for(;i < len; ++i)

    {

        postfix[j] = '\0';

        printf("Current Output: %s\n",postfix);

        curr = infix[i];

        if(IsOperator(curr))

        {

            PrintStack(S);

            if (curr == ')')

            {

                while('(' != (top = Pop(S)))

                    postfix[j++] = top;

                

            }else if(curr == '^')

            {

                top  = Top(S);

                while(top != '^' && 

                    (GetOperatorClass(curr) <= GetOperatorClass(top)) && 

                    top != '(')

                {

                    postfix[j++] = top; Pop(S);

                    top = Top(S);

                }

                Push(S,curr);

            }

            else

            {

                {

                    top = Top(S);

                    while((GetOperatorClass(curr) <= GetOperatorClass(top)) && top != '(')

                    {

                        postfix[j++] = top; Pop(S);

                        top = Top(S);

                    }

                }                

                Push(S,curr);

            }

            

        }

        else

            postfix[j++] = curr;

    }

    while((top = Pop(S)) != 0)

        postfix[j++] = top;

    postfix[j++] = '\0';

    printf("%s",postfix);

    return 0;

}