栈实现表达式求值（c/c++/python）

算法逻辑：

OperandType EvaluateExpression(){
    //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
    InitStack(OPTR); Push(OPTR, '#');
    InitStack(OPND); c = getchar();
    while(c != '#' || GetTop(OPTR) != '#'){
        if(!In(c, OP)){Push((OPND, c)); c = getchar();}//不是运算符进栈
        else 
            switch(Precede(GetTop(OPTR), c)){
                case '<'://栈顶元素优先权低
                    Push(OPTR, c); c = getchar(); break;
                case '='://脱括号并接收下一字符
                    Pop(OPTR, x); c = getchar();
                case '>'://栈顶元素优先权高, 退栈并将结果运算入栈
                    Pop(OPTR, theta); Pop(OPND, b); Pop(OPND, a);
                    Push(OPND, Operate(a, theta, b)); break;
            }
    }
    return GetTop(OPND);
}

---

算法实现:

1. c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

#define MAXSIZE 100
const char* OPERATOR_SET = "+-*/()#";

typedef struct {
    int data[MAXSIZE];
    int top;
} OperandStack;

void initOperandStack(OperandStack *s) {
    s->top = -1;
}

int pushOperand(OperandStack *s, int elem) {
    if (s->top == MAXSIZE - 1) {
        fprintf(stderr, "Stack Overflow\n");
        return -1;
    }
    s->data[++s->top] = elem;
    return 0;
}

int popOperand(OperandStack *s) {
    if (s->top == -1) {
        fprintf(stderr, "Stack Underflow\n");
        return -1;
    }
    return s->data[s->top--];
}

typedef struct {
    char data[MAXSIZE];
    int top;
} OperatorStack;

void initOperatorStack(OperatorStack *s) {
    s->top = -1;
}

int pushOperator(OperatorStack *s, char elem) {
    if (s->top == MAXSIZE - 1) {
        fprintf(stderr, "Stack Overflow\n");
        return -1;
    }
    s->data[++s->top] = elem;
    return 0;
}

int popOperator(OperatorStack *s) {
    if (s->top == -1) {
        fprintf(stderr, "Stack Underflow\n");
        return -1;
    }
    return s->data[s->top--];
}

char peekOperator(OperatorStack *s) {
    if (s->top == -1) {
        fprintf(stderr, "Stack Underflow\n");
        return -1;  // Use an invalid character to indicate error
    }
    return s->data[s->top];
}

int isInOperatorSet(char c) {
    return strchr(OPERATOR_SET, c) != NULL;
}

int precedence(char op1, char op2) {
    static const char precedence_table[7][7] = {
        {'>', '>', '<', '<', '<', '>', '>'},
        {'>', '>', '<', '<', '<', '>', '>'},
        {'>', '>', '>', '>', '<', '>', '>'},
        {'>', '>', '>', '>', '<', '>', '>'},
        {'<', '<', '<', '<', '<', '=', ' '},
        {'>', '>', '>', '&g