中缀表达式转后缀表达式c++代码

我可以回答您的问题，以下是将中缀表达式转换为后缀表达式的C代码示例：

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

#define SIZE 100

char stack[SIZE];
int top = -1;

void push(char item) {
    if (top >= SIZE - 1) {
        printf("\nStack Overflow.");
    }
    else {
        top = top + 1;
        stack[top] = item;
    }
}

char pop() {
    char item;

    if (top < 0) {
        printf("stack under flow: invalid infix expression");
        getchar();
        exit(1);
    }
    else {
        item = stack[top];
        top = top - 1;
        return (item);
    }
}

int is_operator(char symbol) {
    if (symbol == '^' || symbol == '*' || symbol == '/' || symbol == '+' || symbol == '-') {
        return 1;
    }
    else {
        return 0;
    }
}

int precedence(char symbol) {
    if (symbol == '^') {
        return (3);
    }
    else if (symbol == '*' || symbol == '/') {
        return (2);
    }
    else if (symbol == '+' || symbol == '-') {
        return (1);
    }
    else {
        return (0);
    }
}

void infix_to_postfix(char infix_exp[], char postfix_exp[]) {
    int i, j;
    char item;
    char x;

    push('(');
    strcat(infix_exp, ")");
    i = 0;
    j = 0;
    item = infix_exp[i];

    while (item != '\0') {
        if (item == '(') {
            push(item);
        }
        else if (isdigit(item) || isalpha(item)) {
            postfix_exp[j] = item;
            j++;
        }
        else if (is_operator(item) == 1) {
            x = pop();
            while (is_operator(x) == 1 && precedence(x) >= precedence(item)) {
                postfix_exp[j] = x;
                j++;
                x = pop();
            }
            push(x);
            push(item);
        }
        else if (item == ')') {
            x = pop();
            while (x != '(') {
                postfix_exp[j] = x;
                j++;
                x = pop();
            }
        }
        else {
            printf("\nInvalid infix Expression.\n");
            getchar();
            exit(1);
        }
        i++;

        item = infix_exp[i];
    }
    if (top > 0) {
        printf("\nInvalid infix Expression.\n");
        getchar();
        exit(1);
    }
    postfix_exp[j] = '\0';
}

int main() {
    char infix[SIZE], postfix[SIZE];

    printf("Enter Infix expression : ");
    gets_s(infix);

    infix_to_postfix(infix, postfix);
    printf("Postfix Expression: ");
    puts(postfix);

    return 0;
}

希望这能帮助您。